The Only Bug in the Sea
Only one group of insects has taken to the sea—the small, gray long-legged water striders. Unlike fresh water relatives of the same genus, these have permanently lost their wings. They have no further use for this means of movement in the ocean.
Great numbers have been found floating and swimming in the open sea around Pacific islands. Both nymphs and adults sometimes are blown onto the beaches by strong winds. They are awkward on land, seek shelter in any depression in the sand, and fall easy prey to birds and the multitude of ghost crabs which glide over the sands after dark.
On the surface of shallow water the insects are found in groups of hundreds of thousands. Apparently they feed on plankton which rises to the surface at night. They themselves are not eaten by fish. This is probably due to scent glands which secrete a strong odor which is repellant to the ever hungry vertebrates.
In small embayments are found enormous numbers of one type of water strider, the female of which is less than a twelfth of an inch long. The male is considerably smaller and rides on the back of his mate to ensure that the two will not be separated by wind or tide.
Insects are by far the most abundant of all land animals; the reasons why only one genus has invaded the sea have been the subject of much speculation. On the continents, insects are found in salt water lakes where the saline concentration is much greater than in sea water. Other types live in torrential streams and waterfalls where they get much rougher treatment than would come from wave action. There are two probable reasons for the failure to invade the ocean. One is the fact that no insect ever has been able to live in very deep water. The “bug” race has evolved a special breathing mechanism admirably suited to life on land but rather poorly adapted to life under water. Besides, the seas have been taken over almost completely by the remote relatives of the insects, the crustaceans. These include, besides crabs and shrimps, the superabundant copepods, the “lice of the ocean.” Invaders from the land never have been able to compete with them.
A Crocodile With Life After Death
There is an animal that can bite—it might even slash off a man’s arm—after it is dead. Alive it is relatively inoffensive. Being killed makes it positively mad.
Its uncanny ability to bite half an hour or more after its neck has been broken is a major risk for followers of one of the most adventurous of professions—the jungle crocodile hunters. Their story is a saga paralleling that of the Antarctic whalers who first told of Moby Dick. One of the most expert of them is Dr. Fred Medem, Smithsonian collaborator and professor of zoology at the University of Bogota. He has twice been bitten painfully by “dead” reptiles.
The animal is the caiman, smaller than either alligator or crocodile and probably more closely related to the former. Its hide, like that of its two fellow crocodillians, is valuable for leather and during the past few years it has been pursued close to extinction by professional hunters in Colombian and Brazilian jungles and lagoons. Dr. Medem is an eminent zoologist. He doesn’t believe, of course, that any animal that is completely dead can bite off a man’s arm, but he is hard put to explain what he himself has experienced. He thinks that part of the caiman’s nervous system which activates its snout and mouth is somehow disconnected from the rest and does not die at the same time. Thus the dead reptile has no consciousness when it bites. It is a reflex action of one small segment of the nervous system that somehow is not completely dead.
There is only one way to be safe for an indefinite period after the caiman is killed. That is to chop a hole in its neck and run a pointed stick into the medulla oblongata, the reflex action center at the base of the brain. When this is destroyed the ability to bite is lost. One can proceed to skin the animal without fear of losing an arm or a finger. Ordinarily this reptile will not attack a human. It lives on smaller animals—wild and domestic pigs and the pig-like capybaras—that venture into the jungle rivers.
Dr. Medem has recently discovered a curious new sub-species of caimans confined, so far as known, to the upper reaches of the Apaporis river, a tributary of the Amazon. It is much more crocodile-like in appearance than the rest of the family, with a very long, narrow snout. The others have broad, flat snouts. It retains prominent bony ridges over its eyes—one of the most striking characteristics that distinguish the caimans from both crocodiles and alligators.
A much more dangerous animal is the Orinoco crocodile, a large reptile which lives only in the Orinoco and its tributaries and has a taste for human flesh. The creature is especially dangerous to bathers and to women doing their washing in the rivers. This is one of the two species of these dreaded reptiles known in South America. The other is a smaller, less aggressive creature of seashore rivers and lagoons. The inland species now is quite close to extermination. Until recently it was pursued by both German and French companies of professional crocodile hunters. Now they have given up because the profits have become too small for the risk.
The technique for hunting caimans and crocodiles is strikingly like that of the whale hunters and just as dangerous. The hunter goes out on the river with a boat at night. The boat carries searchlights which move over the surface of the water. Here and there appear glittering red and yellow spots. The red spots are the eyes of crocodiles, the yellow ones eyes of caimans. The boat is propelled by jungle Indians who have developed the ability to paddle noiselessly. They row to within about two yards of a pair of glittering eyes. Then the hunter throws his harpoon, equipped with a special aiming apparatus. He has developed skill in hitting precisely the right spot, judged by the position of the eyes. For a crocodile he aims at where the neck should be, for a caiman at the flank. The neck of the latter reptile is protected by heavy scales. A gun never is used. The wounded reptile simply would dive into deep water where its body could not be recovered. After the harpoon, with a rope attached, finds its mark there is a terrific struggle as the reptile tries to get into deep water. The caiman finally is “killed” by chopping through its spinal cord with a machete. That is, everything is dead except the brain and the snout. The spine of a crocodile is broken by a blow with a large ax just behind the shoulders. It stays dead.
The caimans migrate overland from lagoon to lagoon during the dry season. When at last they find water they dig holes in the mud and sleep until the heavy rains return, when they emerge and resume their normal ways of life. Quite exciting stories are told of persons who happen to meet migrating bands of these “barbillos”, creatures about three feet long. Ordinarily they will not attack humans but they will not hesitate to do so if they feel they are threatened. Once one of them gets a grip it is almost impossible to break away unless one happens to have a machete.
The Salamander That Lives Like a Worm
There is an animal related to the salamander and the frog which looks like a gigantic earthworm and lives an earthworm’s life. It is seen so rarely that probably not one person in a million is aware of its existence.
It is the caecilian, a very ancient creature forming the third branch of the order of amphibians which were probably the first back-boned animals to establish themselves on land nearly 300,000,000 years ago. There are about fifty species. Caecilians are found in most of tropical America, Africa and Asia. They range in length from a few inches to nearly a yard. The larger ones might be mistaken either for titanic earthworms or small snakes. In the physical structure are combined features of both salamanders and frogs.
These amphibians spend all their lives burrowing in the soil. They live chiefly on earthworms and come to the surface only for brief intervals after heavy rains. They usually are seen only by farmers who uncover them while ploughing, or digging ditches. Since they are so easily mistaken for snakes they are avoided, although they are entirely harmless. They have sharp teeth but make no effort to bite when handled.
Most of the caecilians are egg-layers, the large eggs being attached to one another like beads on a string and then wound up in a ball. This is incubated by the mother who coils herself around it. The burrows where the eggs are laid are always on a stream bank since the young, like those of all amphibians, must pass part of their development stage in water. These amphibians probably are fairly abundant animals. Owing to the subterranean life they are nearly, perhaps in some cases completely, blind.
The amphiuma, a species of salamander, also is often mistaken for a snake. It spends most of its life in rivers buried in mud, where it lives on larvae and on fish eggs. Since it is an air-breathing creature it must come to the surface frequently to breath.
The amphiuma has rudimentary legs, almost microscopic in size. This fact alone is enough to differentiate it from the snakes, who always are legless.
This curious salamander is seldom encountered and is barely mentioned in standard textbooks of natural history. Confined to the southeastern United States, it often is considered a highly poisonous animal. Actually it is harmless. Very rarely one is caught on a fishhook. It is so slippery that it is almost impossible to hold in the hand.
The creature has some relatives which are not so secretive in their habits and are much better known. One is the giant salamander of China and Japan, the largest and most active of the race. It makes its home in crevices under rocks in running streams. Another is the “mud puppy” or “hell bender” which sometimes gets on the hooks of fishermen in muddy streams.
The amphiuma is a degenerate member of the family. It has almost lost its legs. It still retains its eyes, but these have become very small. The animal can have very little use for them.
In India is found a wormlike caecilian, Ichthyopis, which lives under stones and burrows after the fashion of earthworms. Superficially it differs from an earthworm by its darker color. Its body is coated with slime and it leaves a trail of mucous behind it when it crawls.
The earth snake Silybura is found in the same region. It usually is mistaken for a worm, especially by birds to their own discomfort and sometimes disaster. It ties itself in loops around a bird’s feet and these loops are quite difficult to loosen. Among natives there is a superstition that if it coils around a child’s finger the only way to get rid of it is to amputate the member.
Three-eyed Lizards of New Zealand
Among sun-baked rocks on barren islands off the New Zealand coast basks a solitary survivor of the days before the dinosaurs. It is earth’s oldest back-boned inhabitant, a fugitive in time from nature’s harsh law of the survival of the fittest—the tuatera, or three-eyed lizard. Its big, dreamy hazel eyes have watched the procession of the ages for 300,000,000 years—the beginning and extinction of the dinosaurs to whom it stood in about the relationship of a great uncle, the coming of birds and mammals, milleniums of famine and milleniums of plenty, the shattering and crashing together of continents. It has survived while all its contemporaries of the earth’s ancient days have died, largely because it has been willing placidly to watch the parade pass without bothering to take any part in the tumult and shouting.
The feature of great interest about the tuatera, both popularly and scientifically, is its third eye. This third, or pineal, eye is closer to its original form in the tuatera than in any other living creature. Just after the little reptile is hatched the organ appears as a dark spot under a film of thin, semi-transparent skin. In a baby tuatera it becomes a small knob on top of the head. Thick, opaque skin covers the eye in the adult reptile and it is difficult to distinguish. Anatomists doubt whether the animal actually sees with the pineal eye any more. The fact remains that this organ can be distinguished easily and that it retains, in degenerated form, the characteristics of a seeing eye which has nerve connections with the visual cortex at the back of the brain. Moreover, when the third eye of an infant tuatera is dissected there is clear evidence that it once was a double organ.
The tuatera is about two feet long from its snout to the tip of a crocodile-like tail. It has a scaly skin with a row of spines along its back. Its large hazel eyes are its most conspicuous feature. They have a soft, dreamy expression, and they never appear to blink. There are no external ears, but the sense of hearing is highly developed. One way of drawing the creature from its burrow is to play a tune on almost any instrument.
It does not dig its own holes under the rocks. Usually it shares the burrow of a black-and-white petrel—known in New Zealand as the mutton-bird—and it remains there even when the bird incubates its eggs and feeds its nestlings. Apparently a mutually satisfactory arrangement has been reached between petrel and lizard. The former usually are in their nests only at night. The tuatera spends most of the night away from home, hunting for the insects which are its favorite food. Occasionally, it has been observed, a host will become tired of his persistent house guest and try to evict it. In such a case the tuatera never puts up a fight. It leaves placidly and tries to find some other petrel with whom it can share quarters. If this search fails it will, as a last extremity, scoop out its own burrow, although apparently such labor is against its deeply fixed principles of making no effort which possibly can be avoided.
The lizard goes to sleep about the middle of April, the beginning of winter in New Zealand, and wakes late in August, when spring is well underway. Then for seven months it grows fat on insects.
The creature is reportedly capable of living for 500 years and more. It shares its longevity with its distant relatives, the great turtles. Its long life, during most of which it continues to breed, doubtless has been a major factor in its racial survival.
The ancient reptiles were plentiful when white men first came to New Zealand early in the last century. The Maoris regarded them with superstitious awe and avoided them as much as possible. But early British settlers and their dogs used to kill the inoffensive creatures for sport. This was the first active enmity the tuateras ever had known. They saved themselves by withdrawing to the barren islands and becoming even more seclusive in their ways of life. Thus they clung to a thin thread of existence until an enlightened government threw the protection of the law around them.
Today the three-eyed lizard is probably the world’s most rigidly protected animal. The New Zealand government has placed all sorts of legal restrictions on hunting or capturing it, and to kill one would be a major crime. For that matter, very few persons living ever have seen a tuatera. It stays in seclusion most of the time. There is a single specimen in the zoological park at Wellington. When a party from a Byrd Antarctic expedition visited there they were told that the lizard had not been seen for several months and that it was highly improbable that it could be lured out of hiding. One day it would appear of its own volition, take a philosophical look at the twentieth century, eat a few flies, and retire to its lair under some rocks again. Here probably is the secret of the race’s longevity. The little lizard has spent most of its time sleeping. It has existed with the minimum of effort. It has been satisfied with its lot and, above all, it never has gotten in the way. It has been observed, for example, that one of the creatures never climbs over even the smallest obstacle. It always will walk around.
Prodigious Fertility of Insects
The capacity of insects to reproduce is almost incalculable. A single over-wintering house fly theoretically might have 5,598,729,000,000 descendants in a single year. It has been calculated that a single cabbage aphis, which weighs less than a thirtieth of an ounce, might give rise in a year to a mass of descendants weighing 822,000,000 tons, about five times as much as all the people in the world. Fortunately nearly all insects have an enormous mortality rate.
The Lizard That Runs Out of Its Own Skin
There is an animal that can get out of its own skin. It is a little brown lizard, a gecko, which lives in native houses on the Palau Islands in the South Pacific. This creature, about six inches long, is closely related to the house geckos, which are found throughout the tropical Pacific islands and as far north as Florida in the New World. The Palau species is almost impossible to capture by hand.
Grabbed by the tail, it immediately sheds that organ. This is a rather common practice among certain lizards and apparently brings little inconvenience. A new tail can be grown. But as soon as a hand is laid on this particular species it immediately and literally “runs out of its skin.” This is done with lightning-like rapidity. The would-be captor is left holding the animal’s empty skin. All the rest of the lizard is running away, presumably seeking a hiding place.
This “running out of the skin” is a far different phenomenon than that of shedding the skin by various reptiles, which always takes place after a new skin has been formed underneath. The gecko just abandons its skin altogether. It flays itself alive. Escape in this way apparently is suicidal in most cases. That it ever could grow back a complete skin is highly improbable.
High Living in the Himalayas
The highest land-dwelling animals on earth are small, black attid spiders. They live in islands of broken rock on Mount Everest at an altitude of 22,000 feet. This is far above the line of perpetual snow and nearly a mile above the last vegetation. Since there is no other living thing near them, they have to eat one another for sustenance. Presumably their ranks always are being repleted by new arrivals from below.
Highest of all living things are red-legged, black-feathered choughs, birds of the crow family. A lone chough has been seen in the Himalayas at 27,000 feet. There is an intimate association between these birds and mountain sheep. The chough sits on the sheep’s back and searches its hair for insects. The sheep seems to like this attention and stands still while the exploration is in progress.
Another bird-animal association at high mountain altitudes is that between mouse hares, rabbit-like animals about the size of large rats, and finches. The hares live in burrows and usually are seen feeding at the entrances or running from hole to hole. Both hares and birds are seed eaters.
Wild sheep and mountain goats in the Himalayas struggle up to about 17,000 feet. There are small, wingless grasshoppers at 18,000 feet. A few bees, moths and butterflies are found at 21,000 feet.
Barking Spider Monkeys
Barking spider monkeys that fight off unwelcome human invaders are dominant animals in the “green mansions” of Panama jungles. They live in semi-nomadic troops, each of which occupies a fairly restricted area of the forest, sometimes overlapping slightly with areas of other groups. Within their territory members of a troop wander freely, but their activities tend to center around food and lodge trees.
In reporting on his observations of their activities Dr. C. R. Carpenter of Columbia stated: “Almost every night the group slept within earshot of camp. For eight successive nights they returned to the same group of trees. Throughout the day the troop travelled, in general, over the same routes from one food tree to another and from favorite places in the deep forest where the midday siesta occurred. Several other groups were regularly located in their own particular home areas.”
The monkeys resent intrusion of their territories by anything that looks like another monkey, such as a man. When approached they start barking. The usual terrier-like bark of great excitement may change to a metallic chatter repeated with great frequency. When males, and sometimes adult females are approached closely they growl in a strikingly vicious manner. Typically they come to the terminal ends of branches, often within 40 to 50 feet of the observer, and vigorously shake these branches. Both hands and feet may be used while the animal hangs by its tail.
Throwing of branches is a conspicuous part of the reactions to men. Quite frequently they break off and drop limbs close to the intruder. Green branches sometimes, but most often large dead limbs weighing up to ten pounds may be dropped. “This behavior,” according to Dr. Carpenter, “cannot be described as throwing although the animal may cause the object to fall away from the perpendicular by a sharp twist of its body or a swinging circular movement of its powerful tail. This dropping of objects from trees may be considered as a defensive adaptation arising from the more generalized habit of shaking branches. A significant variation occurs when the animal breaks off a limb and holds it for a time—from a second to half a minute—before letting it fall.”
Normally the monkeys travel along the upper surfaces of limbs, using all four feet and carrying the tail arched over the back. When crossing from one tree to another they use their powerful tails to support themselves from limbs. During such movements hands, arms and tails are used at the same time to make contacts with supports. The monkeys have a strong tendency to keep their heads upward. Therefore, when coming down a perpendicular limb, vine or tree trunk they go backwards rather than head foremost. They frequently make long jumps outward and downward, covering at times more than thirty feet
The Insect That is Born Pregnant
Among nature’s weirdest tricks is the strange phenomenon known as merokinosis, reported for a single family of almost microscopic insects. The little creatures are fathers and mothers before they are born. They are a species of mite which infests grass. They belong to a family which, almost alone among insects, gives birth to living young.
Nearly all insects are egg layers. The eggs, usually deposited in enormous numbers, hatch outside the body of the mother. Then the individuals go through a series of metamorphoses—nymph, larva and the like—before reaching their own reproductive maturity.
These grass mites, however, are born fully adult animals. A sack on the body of the female swells until it is about 500 times the original body size. It is filled with eggs and a nutritive fluid. Within this sack the eggs hatch and the new generation passes through all the ordinary stages of insect metamorphosis. Finally, when they are fully mature, the mother dies, the sack breaks, and the host of new mites emerges.
It was long thought that the mites were striking examples of parthenogenesis, or asexual reproduction. Females isolated as soon as they were born gave birth to large numbers of young. Parthenogenisis is not uncommon among the lower animals. Invariably however, except in this one case, all the offspring are of one sex. The supposedly virgin birth families of the mites contain both males and females in various proportions.
Bull-dog Animals
A repressed tendency towards the bulldog face apparently is deep-seated among mammals. Foxes, cattle and pigs with bulldog appearance have been reported. In three species of dogs—the bulldog, pug and the pug-nosed dog of ancient Peru—this characteristic is dominant. It could have been caused by a pronounced shortening of the rostral portion of the skull due to the failure of facial bones to develop.
Foresight of Kangaroo Rats
A recent report by Dr. William T. Shaw tells of observations of giant California kangaroo rats whose food consists largely of the seeds of pepper grass. The seeds are gathered busily all day and stored in shallow surface caches where they are dried by the dust and heat of the sun. During the night, the animals work busily removing the dried seed to much larger chambers deep underground where it is to be stored for the winter. In some way the highly intelligent animal has learned the secret of preventing mildew. Only a few other animals have mastered the same technique; the beaver and cony dry their twigs in the sun before storing them.
The Primitive Proturans
The proturans—blind, wingless minute bugs found under bark and in leaf litter—are earth’s most primitive insects. They are seldom seen and when they are noticed are likely to be mistaken for larvae of some other insect. So obscure are the creatures that they were not discovered until early in the present century. They are about a twentieth of an inch long, yellowish, and covered with a protective shell of chitin. Sluggish and slow-moving proturans have three pairs of legs, only two of which are used for locomotion. The front pair is held up in front of the insect as it moves. These legs apparently serve the purpose of the antennae found in all higher insect orders. They are provided with primitive sense organs of touch. These little creatures presumably represent one of the earliest stages in insect evolution.
Air-Conditioned Homes of Beavers
Air ventilation of homes appears to be an engineering accomplishment of beavers. “The beaver hut seen from the outside,” according to Sigvald Salveson of Aamli, Nowayd, “appears to be so tight that it seems astonishing that the occupants can get sufficient air. In winter, when the lodge is covered with snow and ice one would not think it possible that the animals could live in apparently air-tight dwellings. Near my home is a small lake where a beaver built a dam and a great lodge. In the outlet of the lake the water was still open and I noticed the footprints of beaver on the thin ice just beyond. Twigs and small trunks were dragged to the open water, where the animals sat on the edge of the ice and took their meals. A fox had his usual track over the lodge.
“More and more snow fell and the hut was more and more hidden under the white blanket. Sometimes I noticed that the fox had gone to the top of the dome and evidently sat there for a while. Near where he had sat was a hole in the snow about half a foot in diameter and with thin ice around the edge. I found that the hole widened downward and ended on the roof of the lodge. At the bottom the hole was at least two feet in diameter and its walls were hard as ice. From this hole or chimney rose warm steam, and the twigs and mud on the roof felt warm and damp to my hand.”
The Demon of Puerto Rico
In deep sunless ravines of Puerto Rico’s Pandura mountains dwells the demon frog. It is a ghostly voice from mountainsides strewn with great, decomposing granite boulders and so thickly covered with tropical vines and bushes that it is almost impenetrable to man. Until twenty years ago it was only a voice, for none of the strange little creatures ever had been seen. The mere sight of the animal, according to many of the natives, would be fatal.
“One might as well try to bribe a mountaineer to catch a ghost as a guajone. There is a strange quality in the voice which probably is largely responsible for the superstitious dread of the mountain people,” according to Smithsonian Institution biologist Gerrit S. Miller, Jr.
“It is strange enough when heard from the surface,” Miller reports, “but it becomes even more strange after one has climbed down into the irregular and dangerous openings, which prove to be much larger and more cavernous than the surface appearance, with its dense and deceptive covering of vegetation, could lead one to expect. With flashlights the frogs are easily found and caught as they crawl slowly over the damp, but not slippery surface of the granite.
“To the natives they are objects of dread. One man said they were about a foot long and armed with frightful teeth. Another assured me that anybody who saw one would die shortly afterwards. No offer of money could induce the boys or men to go into the cavities in search of them.”
The little creature is fantastic in appearance, chiefly due to its large protruding eyes. The edge of the eyelid is white, making a thin white line around the eye. The iris is back and gold. The skin is light brown above and nearly white underneath, but some specimens have blotches of yellow which add to the weird appearance.
Living as they do in the semi-darkness of mountain gullies, little is known of the life history and habits of these strange creatures. The most notable characteristic of several specimens kept alive for observation was the peculiar singing in a liquid note repeated six or seven times. It can best be imitated by whistling. This singing is believed to be part of the courtship behavior of males.
The demon frog has been given the scientific name of Eleutherodactylus cooki. It appears to have been especially adapted for life among the boulders of its restricted habitat.
Man-Made Plants
At least a half dozen species of plants are man-made. They are hybrids which can transmit their basic and unique characters to future generations.
The fact that what long was considered an impossibility in the plant kingdom has been achieved is revealed by Dr. H. Bentley Glass, professor of biology at Johns Hopkins University. With newly developed techniques which make possible the doubling of chromosomes, bunches of genes which are the units of heredity, the creation of species may be just at its threshold and man may take over control of evolution.
The definition of species, after all, is the ability to produce offspring with the major characteristics of the parents. The first successful attempt, Dr. Glass says, was by a Russian geneticist about 30 years ago. He crossed a radish and a cabbage and produced a “rabage.” When two rabages were mated they produced seed which sprouted into other rabages.
Unfortunately for the man who had been the first to cross one of the great barriers in biology, the rabage was a pretty poor specimen. It had the prickly, uneatable leaves of the radish and the poor root system of the cabbage. Russian agricultural authorities had been led to expect great things. They were bitterly disappointed that the new vegetable did not fit into one of the five-year plans. The geneticist was not heard of again and it is generally believed that he was “eliminated” as a reward for one of science’s greatest achievements.
Creators of new species have fared somewhat better in other countries, especially the United States, but they have not fared too well anywhere. In practically every case the new species they have created have taken over the worst characters of the parent species. They have been of no commercial value. It is likely that about the same thing has happened in nature throughout the milleniums.
But bad may be good. It all depends on the environment into which the new species is born. Under the right circumstances, the rabage might have superseded both radish and cabbage. That is, it might have been adapted to a change in environment in which both parent species would have become extinct.
Although no new animal species has yet been man-made there seems no overwhelming reason why this should not happen with some of the new chromosome-doubling drugs. However, a new kind of man is not likely. Among higher animals the mechanism of heredity is very complex indeed. It isn’t likely to happen in nature, in the face of atomic radiation. It has been calculated that normally there is one human mutation per generation for each 50,000 individuals. The high probability is that this mutation involves a recessive, or hidden, gene. Its effects do not appear in the population until two persons carrying the same recessive are mated. About 999 out of 1,000 recessive genes are “bad” and in due course will cause the extinction of the line in which they appear. In the long history of the race it is likely that everybody has fallen heir to one lethal gene, but it may be a long time making its appearance in family lines.
Most of the genes in any given population, good or bad, are so hidden that it is practically impossible to predict what the offspring of any particular couple will be.
The recessive genes have vastly increased through the operation of human “melting pots” all over the world in the last few generations. One result is that minority races tend to become absorbed in majorities. Thus the relatively small American Negro population, without any further inter-marriage but purely through the cropping out of recessives already received from the white majority, will be entirely amalgamated in the more numerous race in approximately 2,000 years.
Genetics is getting into the hands of scientists tools which can speed up the natural process of change about 1,000-fold and this may result in either good or evil. The good side is well illustrated by hybrid corn—a plant which cannot be considered a new species. This lately has been carried to the point where corn with much more sugar in its stalks and only six instead of twelve feet high can be produced.
The Great Seal Migration
The great annual northward migration of the seals is one of the most remarkable phenomena of animal life. It seems to be without organization and without leadership. Yet toward the end of March each year the hundreds of thousands of cow seals and pups scattered over thousands of square miles of water start at about the same time in three great groups bound for three specific places. It has been the same for centuries, perhaps milleniums. Each animal moves at about the same rate so that all arrive within a few days of each other. Unlike birds, they do not move in compact masses. Three great herds exist.
The American herd of about 1,500,000 is by far the largest of the three. It goes straight to the Pribiloffs, where it goes ashore on two almost barren islands—St Paul and St George. The Japanese herd, numbering about 40,000, makes for Robben Island, off northern Japan. The Russian herd, now estimated at about 200,000, goes to a few rocky islands of the Commander archipelago off Kamchatka.
The moving herds consist almost entirely of females and young. The bulls winter further north, tend to be solitary during the winter, and precede the cows to the summer homes. The breeding season lasts for about two months. During this time the bull never eats or touches a drop of water. He never leaves the land. He arrives sleek and fat from the ocean pasture and is able to survive entirely on stored energy. This keeps him alive, even when he fights scores of terrible battles with younger rivals. Towards the end of summer he naturally is a sorry looking creature.
One day, actuated by some common impulse, cows and calves depart. Then the bulls, their arduous labors of race propagation over for ten months, draw back among the rocks for a long rest.
The Magic Bark of the Cinchona Tree
The shadow of a pale Spanish lady, dead for almost three centuries, has returned to the dense rain forests of the western slopes of the Andes.
The shadow is that of the Countess of Chinchon, wife of the redoubtable Don Luiz Geronimo de Cabrera Bobadilla y Mendoza, colonial viceroy of Peru. She was dying of a strange disease in Lima in 1638. Her Jesuit confessor, the story goes, gave a medicine to her doctor made from the bark of a common Peruvian tree. It supposedly saved her life and two years later she returned to Spain, carrying with her some of the magic bark. Thus she gave to the world one of the supreme medicines of all times. A century later the Swedish botanist Linnaeus tried to pay a compliment to the long-dead beauty but misspelled her name—calling her tree “cinchona”. Out of it came quinine.
The Andean forests remained for 200 years the only source of the magic drug—quinine. The cinchona trees grew wild. They were stripped of bark recklessly and became very scarce. By 1850 the price of quinine was $50 an ounce and only the rich could afford to have malaria.
The British tried to transplant the tree in India and failed. Then Dutch botanists obtained some seed, planted it in the East Indies, and developed high-yielding species. Soon this region became the sole source of the world’s supply. The price dropped to 18 cents an ounce and the lands over which the long-dead Countess had ruled dropped out of the picture.
Now South American countries, notably Venezuela and Bolivia, are reclaiming the crop with improved varieties of the cinchona tree, equal to the best produced by the Dutch. They are regaining rapidly the dead lady’s gift.
Colombia’s Ant Tree
In the sparsely inhabited, tropical portion of eastern Colombia is an ant tree known as the barrasanta. It is a small, slender tree with showy, red flowers which grows 25 to 30 feet in height. Both trunk and branches are hollow and filled with masses of vicious, biting ants. As soon as the tree is disturbed the insects swarm upon the invader. As a result the tree is generally left alone both by Indians and white settlers. The ants are protected by the branches and in turn protect the host with their fighting prowess.
A curious shrub which grows out of enormous anthills found through the llanos region of western Colombia furnishes quite a different example of insect-plant association. The ants are “leaf cutters.” All other plant life avoids their immediate neighborhood. This particular shrub exudes a viscous, milky juice which traps any ants which try to climb toward its leaves. Hence the insects have learned to leave it alone and it enjoys the rich ant hill soil without competition from any other plants.
The Strange Behavior of Plants
The behavior characteristics of some American plants are strange indeed.
The compass plant, a bristly perennial of the aster family which grows in abundance over the prairies, is a living compass. It turns the edges of its leaves in a general north-south direction. Another American plant, the wild lettuce, does the same thing. The result is that when the intensity of sunlight is weakest in the morning and evening the flat surfaces of the leaves are in a position to receive the maximum available amount of light. At noon, when there is more light than the plant needs, only the edges of the leaves are turned towards the sun.
Then there is the English ivy which arranges its leaves in a mosaic pattern so that about the greatest possible area is exposed to the light. Other plants show equally precise adaptations to their light requirements.
It is all associated with the process of photosynthesis—i.e., the manufacture by the plant of carbohydrates out of carbon dioxide and water in the presence of light. The strength of light needed for this process varies somewhat with the particular plant and its conditions. The phenomenon is one of the most vital in creation, the transformation of the sun’s energy into the fuel of animal life. Without it life would be impossible.
Some plants work under high light intensities, such as those which must adapt themselves on the desert areas of the southwestern United States. Others thrive best in the subdued light of a dense forest. One curious little moss grows in caves where there is almost no light at all. It is equipped with a plate of cells forming a battery of lenses capable of focusing the scattered light on the bodies especially concerned in carbohydrate formation. These are the chloroplasts which contain the mysterious substance, chlorophyll, which acts as a catalyst for action of sunlight on carbon dioxide and water. The shape and arrangement of cells containing the chloroplasts are such that the amount of chlorophyll exposed to the sunlight can be varied.
A specially devised apparatus has been constructed in the Smithsonian laboratory for quantitative studies of the way plants absorb carbon dioxide under different lighting conditions. Not only is the process greatly effected by the intensity of the light, the experiments show, but the wave length also is of paramount importance. The experimental plants are grown with their roots in a nutrient solution and their tops extending into a double-walled glass tube. They are furnished light from surrounding lamps, so that the intensity and wave lengths of the light can be varied as desired. Through the tube, air containing different amounts of carbon dioxide can be passed. Thus every element of the process is under rigid control of the experimenters.
The experiment already has shown that the correct combination of wave lengths is of the utmost importance in making up synthetic light. Thus, regardless of the intensity, the ordinary electric light when used alone has been demonstrated to be a poor light source. Its maximum energy occurs in the infrared region, below the limit of visibility, while that of sunlight falls in the green-blue region. If tomato plants are grown under high powered Mazda lamps in the Smithsonian’s special growth chambers, especially when the humidity is high, their leaves turn pale and almost white. Chlorophyll disappears under these conditions.
Venezuela’s Nocturnal Orchid
A flower that opens only by moonlight is one of Venezuela’s plant curiosities. It is an ivory-white, velvety orchid which depends entirely on nocturnal butterflies to sip its nectar while pollenization takes place.
The plant is one of 800 species of Venezuelan orchids. Among these is probably the prettiest and rarest of the orchid family, the mother-of-pearl flower, which can sometimes be found in the deep jungles of the Gran Sabana area at altitudes of more than 3,000 feet.
Still another high mountain variety has square petals with fringed edges. Another, found in the jungles of the Upper Orinoco, has blossoms measuring up to 16 inches in diameter. A unique Venezuelan orchid grows only in water.
Throughout the world there are more than 20,000 species of orchids, the great majority of which are found only in mountainous regions of the tropics. A few, however, grow as far north as the Arctic Circle.
The Plant That Strikes Men Dumb
A plant cultivated in the gardens of the Venezuelan National University at Caracas might well be a boon to pestered husbands and harassed mothers.
It is described under the popular Spanish name of “planta del mudo.” It looks like sugarcane. According to the probably exaggerated claims, anybody who chews the stem is stricken dumb for at least 48 hours, presumably due to some paralyzing effect on some part of the vocal apparatus. It is not known whether anybody has tried to extract the marvelous talk-stopping principle.
American botanists are unable to identify the plant. They explain, however, that the northern portion of South America long has been known as the world’s greatest storehouse of plants with strange physiological effects. There is one, for example, alleged to grow hair on bald heads, another which makes everything look red.
Combat of Moth and Shrew
A strange fight between a grey shrew, smallest of North American mammals, and a black “witch moth” has been described by Laurence M. Huey of the San Diego Society of Natural History.
The moth, with a wing spread of about four inches and a body size almost equal to that of the shrew, was placed in a cage with the mammal. The shrew proved too much for the insect after the odds had been equalized by clipping a great part of the latter’s wings.
“Even with this severe handicap”, reports Mr. Huey, “the moth still was very strong and, as its body was so large, the shrew attacked it by grasping one of its wing stubs, tugging with main strength, and hanging on like a bulldog. Once, in a burst of spirited action, the shrew was pitched half way across the cage. This only caused a more determined attack and the moth finally was killed and eaten.
“Another moth, with a body about three-quarters of an inch long, was placed in the cage. It had lost many of the scales from its wings and was partially disabled. It could fly feebly, however, from one side of the cage to the other. The shrew, apparently by its sense of hearing, kept following the course of the moth until its flight carried it about two inches above the little mammal. Then, with an almost invisible quickness, the animal sprang and seized the moth in the air, much as a basketball player leaps to catch a ball high over his head. A few crunches with the sharp-toothed jaws dispatched the moth.”
The Ferocious Snake Weasel
From South Africa comes a report from Dr. Raymond B. Cowles of a fight between a deadly reptile and a little known mammal, the inyengelizi, or snake weasel.
The habitat of the snake weasel, unknown in any zoo, is the Umzumbe Valley in Natal Province, where it is one of the rarest of carnivores. Natives either refuse to bring in inyengelizis or demand exorbitant prices for their skins. All parts of the body are used in the native pharmacopoeia and elders wear a narrow strip of the fur to ward off evil and bring good luck.
Little is known concerning the habits of the animal except that it apparently frequents burrows of subterranean animals in gardens, sometimes is ploughed up, and will attack and kill large snakes.
A reliable Zulu described to Dr. Cowles a fight between one of them and a deadly mamba about seven feet long. He said he had been watching the snake, basking in the sun in a coiled position. After a few moments a movement in the bushes caught his attention and he saw an inyengelizi cautiously stealing towards the snake. When within a foot or two the animal suddenly leaped upon the reptile and fastened its teeth just behind the head where it clung during the ensuing wild struggle. After a few minutes it succeeded in killing the snake, whereupon it relinquished its hold, performed its toilet, and left without eating any of its prey.
The Rabbit That Swims
Life history and habits of a swimming rabbit are the subject of a report to the American Society of Mammologists. The animal is the little known marsh rabbit of the South Carolina coast. It spends most of its life on the tidal marshes and hence, alone of the rabbit family, has become a partially aquarian animal. Almost strictly nocturnal in its habits, its ways of life hitherto have eluded naturalists.
By far the best known trait of the species is its liking for water. Individuals sometimes are encountered in day time far out in one of the coastal rivers. In summer when the water is warm they take to it readily. They seldom are observed, however, swimming in cold water.
In fall and winter the little animal leads a precarious existence. It is the favorite food of the great marsh hawks, continuously circling over the swamps. When Spring comes the birds leave for the North, the sedges grow tall so as to conceal completely the timid little animals, and they are left in peace until the frosts of Autumn.
Generally the marsh rabbit is a home-loving creature but floods in the fresh water area of its habitat sometimes force a migration. It is a natural swimmer. On land it walks with a swimming motion. Other rabbits are practically helpless in the water and try to swim with the hopping motions they use on land. The rare special type appears to be holding its own in spite of its many enemies.
Gorilla Warriors of the Belgian Congo
A study of mountain gorillas in a part of the world which they have all to themselves has been reported by Captain C. S. R. Pitman, British zoologist.
The only humans who ever penetrate the dense forests on the Uganda border of the Belgian Congo, where these animals are found, are pigmies, with whom the great apes live on the best of terms. Captain Pitman is one of the few white men ever to have entered the area.
The mountain gorilla is probably the highest of all the gorillas, next to man. One of the two or three ever in captivity was an infant kept at the National Zoological Park in Washington, D. C. Its brain was the largest ever found in an infra-human creature; it almost matched the smallest normal human brains.
Capt. Pitman found the gorilla quite a likeable and peaceful animal. He says:
“Around the male gorilla, on account of its enormous size and strength, coupled in recent years with frequent lapses from grace provoked by unnecessary and undue interference, there has been woven and unfortunately published a fantasy of inaccuracy and exaggeration—so much so that the very homely old male is visualized as an object of dread. The male gorilla, as the family head, is most solicitous for the welfare of his wives and children—a very human trait. On the threat of danger, he accepts full responsibility for the well-being of his charges.
“If the danger is real the females and young are sent off, while the father waits to take on all comers until satisfied that the remainder of the band are out of harm’s way. Sometimes, when the danger is sudden and overwhelming, the youngsters are sent up trees to hide until the trouble is over. It is strangely reminiscent of the records of some of the early African explorers relative to tribal customs. When the womenfolk were to be seen busily engaged in their usual vocations in the precincts of a village all was well and no hostility contemplated on the part of the local inhabitants.
“But an absence of women and children was interpreted as unfavorable, signifying that they had been removed to a safe place to enable the warriors to fight unhampered. And so it is with the old male gorilla, for as soon as he bids his family seek safety he is out for mischief, although without direct provocation he is unlikely to attack. There are black sheep in every fold and solitary examples both male and female, which probably have been outlaws for a very good reason, have been known to be abnormally aggressive.”
The Biggest “Rat” in the World
Close relative of the porcupine, but without quills, is the aquatic coypu, or nutria, of South America. It has become quite valuable in recent years because of its soft fur. Weighing about 20 pounds, it often is referred to as the “biggest rat in the world”. It shares with the porcupine large, orange-colored incisor teeth which give it a frightful appearance. Like its barbed northern cousin it is a strict vegetarian, living exclusively on water weeds in its native habitat. Before the last war coypu farms were being established through much of Europe. However some apprehension was felt that it might cause considerable damage to crops if it escaped from its enclosures.
The Suicide Marches of Lemmings
Mass death marches of lemmings long have intrigued biologists and psychologists.
The Lapland lemming is a short-tailed animal, related to the meadow mouse, that looks like a miniature rabbit. Through the sub-Arctic winter it lives completely buried under snow through which it burrows in search of mosses and lichens.
It is extremely prolific; females produce two litters of from four to six offspring every year. The numbers soon become far too great to subsist on the sparse supply available in the Scandinavian mountains.
Then, irregularly in periods of from five to ten years, occurs one of the weirdest phenomena of animal life. Acting apparently on a common, sub-conscious, simultaneous impulse, the entire lemming population starts a mass migration out of the mountains to the lowlands. The animals proceed in a straight line, a few feet apart, each usually tracing a shallow furrow in the soil. They are a devouring scourge, stripping the earth of all vegetation in their path. Their progress seems irresistible. No obstacle stops them. If they come across a man they glide between his legs. If they meet with a haystack they gnaw through it. If a rock stands in their way they go around it in a semi-circle and then resume the straight line of their march. When they come to a lake, river or arm of the sea they swim directly across, vast numbers being drowned on the way. If they encounter a boat they climb over it, so as not to be diverted from a straight line. Curiously, they seem to avoid human habitations. They resist fiercely all efforts to stop them. They will bite a stick or hand, crying and barking like little dogs. Multitudes are destroyed every mile of the way. When the migrating horde reaches the sea it moves straight on—to inevitable destruction.
A few linger behind and eventually make their way back to the mountain habitat. Numbers are so reduced that they are seldom observed. Then a new generation starts and builds up for the next migration.
The Ferocity of the Tiger
Symbol of ferocity in the animal world is the tiger. When troops of the American 101st Division entered the German city of Halle in 1945 it probably was considered effective psychological warfare tactics on the part of the Nazis to open the zoo cages and let loose the tigers. So far as known, however, the animals did not attack any Americans.
Whether the reputation of the tiger is entirely justified is debatable. “The tiger”, says Dr. William M. Mann, long-time director of the National Zoological Park in Washington, “is one of the finest animals that lives. In the cage he is the most snobbish of all aristocrats, his contempt for those who jostle in front of his bars being nothing less than magnificent. He is dignity itself. He condescends to no boyish antics to attract attention as does the chimpanzee, to no begging for sweets as do the bear and elephant, to no pacific, philosophic acceptance of fate such as that of the hippopotamus. You cannot win his favor by a stick of candy. He is above rage or gratitude.”
Sometimes adult tigers are captured in traps and sold to circuses. One American circus some years ago had a cage of ten. Their keeper made them perform as another man might spaniels. In the arena they appeared to be a ferocious group. In the menagerie tent, confined in small cages like so many kittens, the keeper could put his hand in their months and rub their teeth. Once he complained bitterly about the tranquility of his charges. “I cannot make a show with ten tame tigers,” he argued. “I must have five mean ones to add to the act.”
The tiger had a prominent part in the menageries of Indian and Chinese monarchs before the Christian era. It first appeared in Europe about the time of the eastern conquests of Alexander. Well known to the Romans, the animal was one of the most dreaded of all the beasts that appeared in the arena.
Despite its supposed ferocity, no great harm has been done in the few cases in which tigers have escaped from zoos. Often they have returned of their own accord.
The Fearsome Porcupine
There are more than 1,000 minute barbs on each of a porcupine’s many quills. This is the reason why such a quill is very difficult to withdraw from the flesh. The armament of quills, from a half inch to three inches long and developed from hairs of the underfur, renders the “spiny pig” of northern woodlands almost immune to attack. About its only enemy in nature is the giant weasel, the fisher, which has learned the trick of quickly turning the porcupine on its back.
The quills are very lightly attached to the porcupine’s body and become detached almost automatically when the creature is attacked. That they can be “shot”, however, is almost certainly a fallacy. A victim must actually be in contact with the animal.
The Plant That Stimulates Visions
In 1560 a Franciscan monk wrote of Aztecs eating a plant called peyotl “which gives them terrible and ludicrous visions, alleviates hunger and thirst, gives strength and incites to battle.” It was used, he reported “to bring about a state of ecstasy in which one had prophetic visions.”
This was the first known reference in literature to the mescal cactus, Lopophora williamsii, whose remarkable effects on the human mind ever since have aroused wonderment. Many have experimented with eating the so-called “buttons” of this cactus and have reported all sorts of terrible and ludicrous visions. But no two experimenters apparently have the same experience. After nearly 400 years the supposed active principle, mescaline, has been extracted and the same effects produced either by swallowing or injection of as little as a half gram.
First comes a decided nausea which lasts about two hours. This passes and is followed by weird hallucinations. One’s own body seems distorted, with some parts exceedingly small and some very large. A common experience is the feeling that only one’s head is the self. The rest of the body is away somewhere in space. The time sense is badly distorted. Minutes stretch out into hours and days, days and hours are contracted into minutes. There are strange optical delusions—lights flashing before the eyes and floating patches of color. Seldom, however, are actual hallucinatory objects seen.
The consumer has the impression that he thinks more clearly than at other times but it has been found that this thought is based more on the sounds than meaning of words. There is a tendency, for example, to argue in puns. An invisible barrier seems to separate one from the rest of the world. This condition lasts for two or three hours, and then passes away, leaving no after affects. The condition has been likened to schizophrenia.
Large doses produce catatonic conditions. A person may sit motionless for a long time in an apparently quite uncomfortable position and refuse to move. Dogs and cats given mescaline injections crouch motionless in corners of their cages, only rousing themselves from time to time to attack invisible assailants.
It recently has been found that only one chemical constituent of mescaline, beta-phenylethylamine, is responsible for the delusions. This is quite similar in chemical structure to the body hormone adrenaline. There have been conjectures that adrenaline may be changed into the mescaline constituent by some as yet unknown process of body chemistry and that this change may be the physiological cause of schizophrenia.
About 40 years ago a peyotl church was set up by Indians in New Mexico. It followed essentially the Catholic ritual, but with mescal buttons substituted for bread in communion. The U.S. Bureau of Indian Affairs did not interfere with the rites when its investigations indicated that the mysterious drug was not habit-forming and apparently caused no physical injury.
The Puzzling Platypus
Fantastic combination of mammal, bird and reptile is the egg-laying, toothless water animal of New South Wales and Tasmania, Australia, the duck-billed platypus. It is clearly a mammal but, with a single exception, it stands quite alone among these warm-blooded animals. The creatures from which it is a survivor probably have been extinct for fifty million years.
It is an animal about twenty inches long from the tip of its horny beak to the end of its broad, flattened tail. It is covered with soft brown fur. Its four legs are short and five-toed. These toes on the front foot are joined by webs like those of aquatic birds which extend beyond the long, sharp, curved toe-nails. On the hind legs of the male are inch-long, sharp spurs through which run minute canals connected with a large gland at the back of the thigh—very much like the poison fangs of a serpent. Yet, so far as can be determined, the gland secretes no poison and the spurs apparently are seldom used in self defense.
The female lays two eggs at a time, each about three-fourths of an inch long and a half inch wide, with strong, flexible white shells. These eggs are not incubated but hatch buried shallowly in sand and straw. The platypus lives on the banks of ponds and quiet streams where it digs burrows as much as 20 feet long with two entrances, one below and the other above the water level. The rear, or land, end of a burrow is enlarged into a small chamber in which the young are reared.
The creatures pass most of the daylight hours asleep in these burrows, curled in rather tight balls. The entrances are concealed in grass and reeds so that the occupants of the burrows are seldom seen. At night the platypus takes to the water. It swims and dives easily and its major food consists of worms and other aquatic animals found in the mud or gravel at the bottom. It has cheek pouches like a squirrel. When it comes up from a dive these pouches are stuffed with the food it has gathered, which is extracted and eaten at leisure.
Adult animals are toothless but in each jaw there is a horny ridge. The young, however, have rootless teeth—a possible clue to their very remote ancestry. Like a bird the platypus has a very small head. There is no division of its brain into two hemispheres, as in all other mammals and most birds. This is a characteristic of the reptile brain.
The creatures can climb with apparent ease. Small groups sometimes are seen sunning themselves on broad tree trunks overhanging the water. They are extremely timid but, when captured, soon become quite tame. In captivity, however, they seldom live long.
The only other member of this animal group is the echidna, or spiny ant eater, of the same part of the world. It is, however, an inhabitant of rocky districts where it digs shallow burrows in sand or hides in rock crevices. The back is covered with sharp, backward-directed spines which give it the appearance of a small porcupine. It has a long, tubular snout from which projects the long, slender tongue covered with some sticky substance. With this it laps up ants and other insects.
Like the platypus, it has short, strong legs with large claws with which it burrows with considerable speed. Burrowing, where possible, is its usual method of flight. Its other defense is to roll itself in a ball, when its sharp spines give it considerable protection. “The only way of carrying the creature”, says George Bennett (Gatherings of a Naturalist in Australasia) “is by one of its hind legs. Its powerful resistance and the sharpness of the spines will soon oblige the captor, attempting to seize it by any other part of the body, to be relinquish his hold.”