The Project Gutenberg eBook of Views of Nature, by Alexander Von Humboldt

71. p. 210—“On the Chimborazo, upwards of eight thousand feet higher than Etna.”

Small singing birds, and even butterflies, (as I have myself witnessed in the Pacific,) are often met with at great distances from the shore, during storms blowing off land. In a similar manner insects are involuntarily carried into the higher regions of the atmosphere, to an elevation of 17,000 to 19,000 feet above the plains. The light bodies of these insects are borne upwards by the vertically ascending currents of air caused by the heated condition of the earth’s surface. M. Boussingault, an admirable chemist, who ascended the Gneiss Mountains of Caracas, while holding the appointment of Professor in the newly established Mining Academy at Santa Fé de Bogotá, witnessed, during his ascent to the summit of the Silla, a phenomenon which confirmed in a most remarkable manner this vertical ascent of air. He and his companion, Don Mariano de Rivero, observed at noon a number of luminous whitish bodies rise from the valley of Caracas to the summit of the Silla, an elevation of 5755 feet, and then sink towards the adjacent sea coast. This phenomenon was uninterruptedly prolonged for a whole hour, when it was discovered that the bodies, at first mistaken for a flock of small birds, were a number of minute balls of grass-haums. Boussingault sent me some of this grass, which was immediately recognised by Professor Kunth as a species of Vilfa, a genus of grass which together with Agrostis is of frequent occurrence in the provinces of Caracas and Cumana. It was the Vilfa tenacissima of our Synopsis Plantarum æquinoctialium Orbis Novi, t. i. p. 205. Saussure found butterflies on Mont Blanc, and Ramond observed them in the solitudes around the summit of Mont Perdu. When MM. Bonpland, Carlos Montufar, and myself, on the 23rd of June, 1802, ascended the eastern declivity of Mount Chimborazo, to a height of 19,286 feet, and where the barometer had fallen to 14·84 inches, we found winged insects buzzing around us. We recognised them to be Diptera, resembling flies, but it was impossible to catch these insects standing on the rocky ledges (cuchilla), often less than a foot in breadth, and between masses of snow precipitated from above. The elevation at which we observed these insects was almost the same as that in which the naked trachytic rock, which projected from the eternal snows around, exhibited the last traces of vegetation in Lecidea geographica. These insects were flying at an elevation of 18,225 feet, or nearly 2660 feet higher than the summit of Mont Blanc: and somewhat below this height, at an elevation of 16,626 feet, and therefore also above the region of snow, M. Bonpland saw yellow butterflies flying close to the ground. The mammalia which live nearest to the region of perpetual snow, are, in the Swiss Alps, the hybernating marmot, and a very small field-mouse, (Hypudæus nivalis,) described by Martius, which on the Faulhorn lays up, almost under the snow, a store of the roots of phanerogamic alpine plants.^[JC] The opinion prevalent in Europe, that the beautiful rodent, the Chinchilla, whose soft and glossy fur is so much esteemed, is found in the highest mountain regions of Chili, is an error. The Chinchilla laniger (Gray) lives only in a mild lower zone, and does not advance further south than the parallel of 35°.^[JD]

Whilst among our European Alps, Lecideas, Parmelias, and Umbilicarias but scantily clothe with a few coloured patches those rocks that are not wholly covered with snow, we found in the Andes, at elevations of 13,700 to nearly 15,000 feet, some phanerogamic plants which we were the first to describe; as for instance, the woolly species of Fraylejon. (Culcitium nivale, C. rufescens, and C. reflexum, Espeletia grandiflora, and E. argentea), Sida pichinchensis, Ranunculus nubigenus, R. Gusmanni with red or orange-coloured flowers, the small moss-like umbelliferous plant, Myrrhis andicola, and Fragosa arctioides. On the declivity of the Chimborazo, the Saxifraga Boussingaulti, described by Adolph Brongniart, grows beyond the limits of perpetual snow on loose blocks of stone at an elevation of 15,770 feet above the level of the sea, and not at 17,000 as has been stated in two admirable English journals.^[JE] This Saxifrage, discovered by Boussingault, must therefore be regarded as the highest growing phanerogamic plant in the world.

The vertical height of Chimborazo is, according to my measurement, 21,422 feet.^[JF] This result is a mean between those which have been given by the French and Spanish Academicians. The principal differences do not here depend on different assumptions for the refraction, but on a difference in reducing the measured line to the level of the sea. This reduction can only be made in the Andes by the barometer, and hence every so-called trigonometric measurement must also necessarily be a barometric one, whose result will vary according to the different formulæ employed. Owing to the enormous mass of the mountain chain, we can only obtain very small angles of altitude, when the greater portion of the whole height has to be measured trigonometrically, and the observation is made at some low and distant point near the plain or the level of the sea. It is on the other hand extremely difficult to obtain a convenient base line, as the space that is to be determined barometrically increases with every step we advance towards the mountain. These obstacles have to be encountered by every traveller who on the high table-lands, which surround the summit of the Andes, selects a spot for performing a geodetic operation. On the pumice-covered plain of Tapia, to the west of the Rio Chambo, at a height of 9477 feet, barometrically determined, I measured the Chimborazo. The Llanos de Luisa, and more especially the plain of Sisgun, whose elevation is 12,150 feet, would yield greater angles of altitude. I had on one occasion made every preparation necessary for the measurement of Mount Chimborazo, from the plain of Sisgun, when the summit of the mountain was suddenly shrouded in a dense cloud.

Some hypothetical suggestions, regarding the probable derivation of the name of the far-famed “Chimborazo,” may not be wholly unwelcome to etymologists. The district in which the mountain is situated is called Chimbo, a word which La Condamine ^[JG] derives from chimpani, to cross a river. “Chimboraço” means, according to him, “the snow of the opposite bank,” from the fact of a brook being crossed at the village of Chimbo, in sight of the huge snow-covered mountain. (In the Quichua language chimpa signifies the opposite bank or side; chimpani to cross a river, bridge, &c.) Several natives of the province of Quito assured me that Chimborazo meant simply the snow of Chimbo. In Carguairazo we meet with the same termination, and it would appear that “razo” is a provincial word. The Jesuit Holguin, whose excellent vocabulary ^[JH] I possess, is not acquainted with the word razo. The genuine term for snow is ritti. On the other hand, my friend, Professor Buschmann, an admirable linguist, remarks that in the Chinchaysuyo dialect, (employed north of Cuzco as far as Quito and Pasto) raju, the j being apparently guttural, signifies snow.^[JI] As chimpa and chimpani do not well suit on account of the a, we may seek a definite meaning for the first portion of the name of the mountain and of the village Chimbo, in the Quichua word “chimpu,” which is used to express a coloured thread or fringe (señal de lana, hilo ó borlilla de colores); the redness of the sky (arreboles), and the halo round the sun and moon. The name of the mountain might be thus derived from this word, without reference to the district or village. At all events, whatever may be the etymology of the word Chimborazo, it should be written in the Peruvian manner Chimporazo, as the Peruvians have no b in their alphabet.

May not the name of this colossal mountain be wholly independent of the Inca language, and have come down from a bygone age? The Inca or Quichua language had not been introduced long prior to the Spanish invasion into the kingdom of Quito, where the now wholly extinct Puruay language had been previously used. The names of other mountains, as Pichincha, Ilinissa, and Cotopaxi, are wholly devoid of meaning in the language of the Incas, and are therefore undoubtedly of higher antiquity than the introduction of the worship of the sun, and of the court-language of the rulers of Cuzco. The names of mountains and rivers belong in all regions of the earth to the most ancient and authentic relics of languages; and my brother, Wilhelm von Humboldt, in his investigations into the former distribution of the Iberian races, has made ingenious use of these names. A singular and unexpected statement has recently been made,^[JJ] “that the Incas, Tupac Yupanqui, and Huayna Capac, were astonished on their first conquest of Quito, to find a dialect of their Quichua language in use among the natives.” Prescott, however, seems to regard this as a very bold assertion.^[JK]

If we could suppose the pass of St. Gothard, Mount Athos, or the Rigi, piled on the summit of the Chimborazo, we should have the elevation which is at present ascribed to the Dhawalagiri in the Himalaya. The geologist who regards the interior of our planet from a more general point of view, and to whom not the directions, but the relative heights of the rocky projections, which we designate mountain chains, appear but as phenomena of little importance, will not be astonished if at some future period mountain summits should be discovered between the Himalaya and the Altai, which should surpass in height those of Dhawalagiri and Djawahir as much as these exceed that of Chimborazo.^[JL] The great height to which the snow-line recedes in summer on the northern declivity of the Himalaya, owing to the heat radiated from the elevated plateaux in Central Asia, renders the mountain, notwithstanding that it is situated in 29 to 30½° north lat., as accessible as are the Peruvian Andes in the region of the tropics. Captain Gerard has moreover recently ascended the Tarhigang as high, if not 117 feet higher,^[JM] than I ascended the Chimborazo. Unfortunately, as I have elsewhere more fully shown, these mountain ascents, beyond the line of perpetual snow, however they may engage the curiosity of the public, are of very little scientific utility.

72. p. 210—“The Condor, that giant among vultures.”

I have elsewhere ^[JN] given the natural history of the Condor, which before my travels had been variously misstated. The name is properly Cuntur in the Inca language; Mañque among the Araucanes in Chili; Sarcoramphus Condor according to Duméril. I sketched the head of this bird from life, of the natural size, and had my drawing engraved. Next to the Condor, the Lämmergeier of Switzerland, and the Falco destructor (Daud.), probably Linnæus’ Falco Harpyia, are the largest of all flying birds.

The region which may be regarded as the common resort of the Condor, begins at the elevation of Mount Etna. It embraces atmospheric strata which are from 10,000 to 19,000 feet above the level of the sea. Humming birds also, which in their summer flights advance as far as 61° north lat. on the western coast of America, and are on the other hand found in the Archipelago of the Tierra del Fuego, were seen by Von Tschudi in Puna at an elevation of 14,600 feet.^[JO] There is a pleasure in comparing the largest and the smallest of the feathered inhabitants of the air. The largest among the Condors found in the Cordilleras, near Quito, measure nearly 15 feet across the expanded wings, and the smaller ones 8½ feet. This size, and the visual angle at which the birds are seen vertically above one’s head, afford an idea of the enormous height to which the Condor soars in a clear sky. A visual angle of four minutes, for instance, would give a vertical elevation of 7330 feet. The cavern (Mackay) of Antisana, opposite the mountain of Chussulongo, and where we measured the birds soaring over the chain of the Andes, lies at an elevation of nearly 16,000 feet above the surface of the Pacific; the absolute height which the Condor reached must therefore be 23,273 feet, a height at which the barometer scarcely stands at 12·7 inches; but which, however, does not exceed that of the loftiest summit of the Himalaya. It is a remarkable physiological phenomenon that the same bird, which wheels for hours together through these highly rarefied regions, should be able suddenly, as for instance on the western declivity of the volcano of Pichincha, to descend to the sea-shore, and thus in the course of a few hours traverse, as it were, all climates. At heights of 23,000 feet and upwards the membranous air-sacs of the Condor must undergo a remarkable degree of inflation after being filled in lower regions of the atmosphere.

Ulloa, more than a hundred years ago, expressed his astonishment that the Vulture of the Andes could soar at heights where the pressure of the atmosphere was less than fifteen inches.^[JP] An opinion was at that time entertained, from the analogy of experiments made with the air-pump, that no animal could exist under this slight amount of atmospheric pressure. I have myself, as has already been mentioned, seen the barometer fall to 14·85 inches on the Chimborazo; and my friend, M. Gay-Lussac, breathed for a quarter of an hour an atmosphere in which the pressure was only 12·9 inches. It must be admitted that man, when wearied by muscular exertion, finds himself in a state of painful exhaustion at such elevations; but in the Condor, the respiratory process seems to be performed with equal facility under a pressure of 30 or of 13 inches. This bird probably raises itself voluntarily to a greater height from the surface of our earth than any other living creature. I use the expression “voluntarily,” since small insects and siliceous-shelled infusoria are frequently borne to greater elevations by a rising current of air. It is probable that the Condor flies even higher than the above calculations would appear to show. I remember observing near the Cotopaxi, in the pumice plain of Suniguaicu, at an elevation of 14,471 feet above the level of the sea, this bird soaring at such a height above my head that it appeared like a black speck. But what is the smallest angle under which faintly illumined objects can be distinguished? Their form (linear extension) exercises a great influence on the minimum of this angle. The transparency of the mountain air is so great under the equator, that in the province of Quito, as I have elsewhere stated, the white cloak (poncho) of a horseman may be distinguished with the naked eye at a horizontal distance of 89,664 feet, and therefore under an angle of thirteen seconds. It was my friend Bonpland whom we observed, from the pleasant country-seat of the Marques de Selvalegre, moving along a black rocky precipice on the volcano of Pichincha. Lightning conductors, being thin elongated objects, are visible, as Arago has observed, from the greatest distances and under the smallest angles.

The account I have given in my Monograph of the Condor (Zoologie, pp. 26–45) of the habits of this powerful bird in the mountain districts of Quito and Peru has been confirmed by a more recent traveller, Gay, who has explored the whole of Chili, and described it in his admirable work, Historia fisica y politica de Chile. This bird which, singularly enough, like the Lamas, Vicuñas, Alpacas and Guanacos, is not found beyond the equator in New Granada, penetrates as far south as the Straits of Magellan. In Chili, as in the elevated plateaux of Quito, the Condors, which usually live in pairs, or even alone, congregate in flocks for the purpose of attacking lambs and calves, or seizing on young Guanacos (Guanacillos). The havoc annually committed by the Condor among the herds of sheep, goats and cattle, as well as among the wild vicuñas, alpacas and guanacos of the chain of the Andes is very considerable. The Chilians assert that this bird when in captivity can endure hunger for forty days; when in a free state, however, its voracity is excessive, and it then, like the vulture, feeds by preference on carrion.

The mode of catching these birds, by an inclosure of palisades such as I have already described, is as successful in Chili as in Peru, for the bird after being rendered heavy from excess of food is obliged to run a short distance with half-extended wings before it can take flight. A dead ox which is already in an incipient state of decomposition, is strongly inclosed with palisades, within which narrow space the Condors throng together; being unable, as already observed, to fly on account of the excess of food which they have devoured, and impeded in their run by the palisades, these birds are either killed by the natives with clubs, or are caught alive by the lasso. The Condor was represented as a symbol of strength on the coinage of Chili immediately after the first declaration of political independence.^[JQ]

The different species of Gallinazos, which are much more considerable in point of numbers than the Condors, are also far more useful than the latter in the great economy of Nature for destroying and removing animal substances that are becoming decomposed, and thus purifying the atmosphere in the neighbourhood of human dwellings. In tropical America, I have sometimes seen seventy or eighty of these creatures collected round a dead ox; and I am able, as an eye-witness, to confirm the fact that has of late erroneously been called in question by ornithologists, that the appearance of one single king-vulture (who is not larger than the Gallinazos) is sufficient to put a whole assemblage of these birds to flight. No contest ever takes place; but the Gallinazos (two species of which, (Cathartes urubu and C. aura,) have been confounded together by an unfortunately fluctuating nomenclature) are intimidated by the sudden appearance and the courageous demeanour of the richly coloured “Sarcoramphus Papa.” As the ancient Egyptians protected the Percnopteri, which purified the atmosphere, so also the wanton destruction of Gallinazos is punished in Peru by a fine (multa) which, according to Gay, amounts in some cities to 300 piastres for every bird. It is a remarkable fact, that this species of vulture, as was already testified by Don Felix de Azara, if trained early, will so accustom themselves to the person who has reared them, that they will follow him on a journey for many miles, flying after his carriage across the Pampa.

73. p. 211—“Encloses their rotating bodies.”

Fontana, in his admirable treatise “on the poison of the viper,” vol. i. p. 62, mentions that he succeeded in restoring to animation, after two hours’ immersion in a drop of water, a wheel-animalcule which had lain in a dried and motionless condition for the space of two years and a half.^[JR]

The so-called reanimation of Rotifera has very recently again been made a subject of lively discussion, since observations have been conducted with more exactness and subjected to a stricter criticism. Baker affirmed that in 1771, he had revived paste-eels which Needham had given him in the year 1744! Franz Bauer saw his Vibrio tritici, which had lain four years in a dry state, move on being moistened. The remarkably careful and experienced observer, Doyère,^[JS] draws the following conclusions from his beautiful experiments: that Rotifera revive, i.e. pass from a motionless state to one of motion, after being exposed to a cold of 11°.2 Fahr., or to a heat of 113° Fahr.; that they preserve the property of reviving in dry sand up to a temperature of 159° Fahr.; but that they lose this property and remain immoveable if warmed in moist sand to 131° Fahr. only;^[JT] and that the possibility of this so-called revivification is not prevented by their being exposed to desiccation for twenty-eight days in barometric tubes, in vacuo, even should chloride of lime or sulphuric acid be employed.^[JU]

Doyère has also seen Rotifera slowly revive after being dried without sand, (desséchés à nu,) a fact which Spallanzani denies.^[JV] “Desiccation conducted in an ordinary temperature might be open to many objections which are not perhaps wholly obviated by the employment of a dry vacuum; but when we observe that the Tardigrades irrevocably perish in a temperature of 131° Fahr. if their tissues are permeated with water, whereas they can, when dried, support a temperature that may be estimated at 248° Fahr., we are disposed to admit that the sole condition required for animal revivification is the perfect integrity of organic structure and continuity.”

In like manner, the sporules, or germinating cells of cryptogamic plants, which Kunth compares to the propagation of certain phanerogamic plants by buds (bulbillæ), retain their power of germination in the highest temperature. According to the most recent experiments of Payen, the sporules of a small fungus (Oïdium aurantiacum), which invests the crumb of bread with a reddish feathery coating, do not even lose their vegetative powers by being exposed in closed tubes for half an hour to a temperature of 183° to 208° Fahr. before being strewn on fresh, unspoilt dough. May not the newly discovered and wonderful monad (Monas prodigiosa), which causes blood-like spots in mealy substances, have been mixed with this fungus?

Ehrenberg, in his great work on Infusoria (p. 492–496), has given the most complete history of all the observations instituted on the so-called revivification of Rotifera. He believes, that notwithstanding all the means of desiccation employed, the organization-fluid still remains in the apparently dead animal. He contests the hypothesis of “latent life”; for death, he says, “is not life in a torpid state, but the absence of life.”

The hybernation or winter-sleep of both warm and coldblooded animals, as dormice, marmots, sand-martins (Hirundo riparia, according to Cuvier)^[JW], and of frogs and toads, affords us evidence of the diminution, if not of the complete suspension, of the organic functions. Frogs awakened from their winter-sleep by warmth, can remain eight times longer under water, without drowning, than frogs in the breeding season. It seems as if the respiratory functions of the lungs require a less degree of activity after the long suspension of their excitability. The circumstance of the sand-martin burying itself during the winter in marshes, is a phenomenon which, while it scarcely admits of a doubt, is the more remarkable, because in birds, the function of respiration is so extremely energetic, that, according to Lavoisier’s experiments, two sparrows in an ordinary condition will, in the same time, decompose as much atmospheric air as a Guinea-pig.^[JX] Winter-sleep is not supposed to be general to the whole species of these sand-martins, but only to some few individuals.^[JY]

As in the frigid zone deprivation of warmth produces winter-sleep in some animals, so in the torrid regions, within the tropics, an analogous phenomenon is manifested that has not hitherto been sufficiently regarded, and to which I have applied the term summer-sleep.^[JZ] Drought and a continuous high temperature act like the cold of winter in reducing excitability. Madagascar, excepting a very small portion of its southern extremity, lies within the tropics, and here, as was already observed by Bruguière, the hedgehog-like Tenrecs (Centeres, Illiger), one species of which (C. ecaudatus) was introduced into the Isle of France (20° 9′, latitude), sleep during excessive heat. The objection advanced by Desjardins, that the time of their sleep falls within the season of winter in the southern hemisphere, can scarcely be regarded as applicable in reference to a country, where the mean temperature of the coldest month is nearly 7° Fahr. above that of the hottest month in Paris; and this circumstance cannot therefore change the three months’ summer-sleep of the Tenrec in Madagascar and Port Louis (Isle of France) into actual hybernation.

In a similar manner, the Crocodile in the Llanos of Venezuela, the land and water Tortoises on the Orinoco, and the colossal Boa, and many of the smaller species of serpents, lie torpid and motionless in the hardened ground, throughout the hot and dry season of the year. The missionary Gilij relates, that the natives, in seeking the dormant Terekai (land-tortoises), which lie buried in dry mud to the depth of 16 or 17 inches, are often bitten by serpents suddenly awakened, and which had buried themselves with the tortoises. An admirable observer, Dr. Peters, who has only just returned from the eastern coast of Africa, writes to me as follows: “I could not obtain any certain information regarding the Tenrec during my short stay in Madagascar, but I am, on the other hand, well aware, that in the portion of eastern Africa where I spent several years, different species of tortoises (Pentonyx and Trionices) remain enclosed for months together, without food, in the parched and indurated ground, during the dry season of this tropical country. The Lepidosiren also remains motionless and coiled up in the hardened earth, from May to December, wherever the swamps have been dried up.”

We thus meet with an enfeeblement of certain vital functions in numerous and very different classes of animals, and, what is peculiarly striking, without the same phenomenon presenting itself in organisms nearly allied, and belonging to one and the same family. The northern glutton (Gulo), allied to the badger (Meles), does not, like the latter, sleep during the winter; whilst, according to Cuvier, “a Myoxus (Dormouse of Senegal, Myoxus Coupeii) which had probably never experienced a winter-sleep in its tropical home, fell into a state of hybernation at the beginning of winter, the first year it was brought to Europe.” This enfeeblement of the vital functions and vital activity passes through several gradations, according as it extends to the processes of nutrition, respiration and muscular movement, or induces a depression of the cerebral and nervous systems. The winter-sleep of the solitary bear and of the badger is not attended with rigidity, and hence the awakening of these animals is easy, and, as I frequently heard in Siberia, very dangerous to the hunters and country people. The recognition of the gradation and connection of these phenomena leads us to the so-called vita minima of the microscopic organisms, which occasionally fall in the Atlantic in showers of meteoric dust, and some of which have green ovaries and are engaged in a self-generating process. The apparent revivification of the Rotifera and of the siliceous-shelled Infusoria is only the renewal of long enfeebled vital functions—a condition of vitality never entirely extinguished, but merely revived by excitation. Physiological phenomena can only be comprehended by being traced through the entire series of analogous modifications.

74. p. 211—“Winged Insects.”

The fructification of diœcious plants was at one time principally ascribed to the agency of the wind. It has been shown by Kölreuter, and also with much ingenuity by Sprengel, that bees, wasps and numerous small winged insects, are the main agents in this process. I use the phrase “main agents”, since I cannot regard it as consonant to nature that fructification should be impossible without the intervention of these insects, as Willdenow has also fully shewn.^[KA] On the other hand dichogamy, sap-marks, (maculæ indicantes), coloured spots indicating the presence of honey-vessels, and fructification by insects, appear to be almost inseparable from one another.^[KB]

The statement often repeated since Spallanzani, that the diœcious common hemp (Cannabis sativa), which was introduced into Europe from Persia, bears ripe seeds without being in the neighbourhood of pollen-tubes, has been entirely refuted by more recent investigations. When seeds have been obtained, anthers in a rudimentary state have been found near the ovarium, and these may have been capable of yielding some grains of fructifying pollen. Such hermaphrodism is frequent in the whole family of Urticeæ, but a singular and hitherto unexplained phenomenon is manifested in the forcing-houses at Kew by a small New Holland shrub, the Cœlebogyne of Smith. This phanerogamic plant brings forth seeds in England without exhibiting any trace of male organs, and without the bastard introduction of the pollen of any other plant. “A species of Euphorbiaceæ,” (?) writes the distinguished botanist, Jussieu, “the Cœlebogyne, which, although but recently described, has been cultivated for many years in English conservatories, has several times borne seeds, which were evidently perfect, since the well-formed embryos they contained have produced similar plants. The most careful observations have hitherto failed in discovering the slightest trace of anthers or even pollen in the flowers, which are diœcious. No male plants of this kind are known to exist in England. The embryo cannot therefore have come from the pollen, which is wholly deficient, but must have been formed entirely in the ovule.”^[KC]

In order to obtain a fresh and confirmatory explanation of this important and isolated physiological phenomenon, I lately addressed myself to my young friend, Dr. Joseph Hooker, who after having accompanied Sir James Ross in his Antarctic voyage, has now joined the great Thibeto-Himalayan expedition. Dr. Hooker wrote to me as follows from Alexandria, at the close of December, 1847, prior to his embarkation at Suez: “Our Cœlebogyne still flowers with my father at Kew, as well as in the Gardens of the Horticultural Society. It ripens its seeds regularly. I have repeatedly examined it with care, but have never been able to discover a penetration of pollen utricles into the stigma, nor any traces of their presence in the latter or in the style. In my herbarium the male blossoms are in small catkins.”

75. p. 212—“Like luminous stars.”

The phosphorescence of the ocean is one of those splendid phenomena of nature which excite our admiration, even when we behold its recurrence every night for months together. The ocean is phosphorescent in all zones of the earth, but he who has not witnessed the phenomenon in the tropics, and especially in the Pacific, can form but a very imperfect idea of the majesty of this brilliant spectacle. The traveller on board a man-of-war, when ploughing the foaming waves before a fresh breeze, feels that he can scarcely satisfy himself with gazing on the spectacle presented by the circling waves. Wherever the ship’s side rises above the waves, bluish or reddish flames seem to flash lightning-like upwards from the keel. The appearance presented in the tropical seas on a dark night is indescribably glorious, when shoals of dolphins are seen sporting around, and cutting the foaming waves in long and circling lines, gleaming with bright and sparkling light. In the Gulf of Cariaco, between Cumana and the Peninsula of Maniquarez, I have spent hours in enjoying this spectacle.

Le Gentil and the elder Forster ascribed these flames to the electrical friction of the water on the vessel as it glides forward—an explanation that must, in the present condition of our physical knowledge, be regarded as untenable.^[KD]

There are probably few subjects of natural investigation which have excited so many and such long-continued contentions as the phosphorescence of sea-water. All that is known with certainty regarding this much disputed question may be reduced to the following simple facts. There are many luminous mollusca which possess the property when alive of emitting at will a faint phosphoric light; which is of a bluish tinge in Nereis noctiluca, Medusa pelagica var. β,^[KE] and in the pipe-like Monophora noctiluca, discovered in Baudin’s expedition.^[KF] The luminosity of sea-water is in part owing to living light-bearing animals, and in part to the organic fibres and membranes of the same, when in a state of decomposition. The first-named of these causes of the phosphorescence of the ocean is undoubtedly the most common and the most widely diffused. The more actively and the more efficiently that travellers engaged in the study of nature have learnt to employ powerful microscopes, the more our zoological systems have been enriched by new groups of mollusca and infusoria, whose property of emitting light either at will or from external stimulus has been recognised.

The luminosity of the sea, as far as it depends on living organisms, is principally owing, among zoophytes, to the Acalephæ (the families of Medusæ and Cyaneæ), to some Mollusca, and to an innumerable host of Infusoria. Among the small Acalephæ (Sea-nettles), the Mammaria scintillans presents us, as it were, with the glorious image of the starry firmament reflected in the surface of the sea. When full-grown this little creature scarcely equals in size the head of a pin. The existence of siliceous-shelled luminous infusoria was first shown by Michaelis at Kiel. He observed the coruscation of the Peridinium. (a ciliated animalcule,) of the Cuirass-monad (Prorocentrum micans), and of a rotifer, which he named Synchata baltica,^[KG] the same that Focke subsequently found in the lagoons of Venice. My distinguished friend and fellow traveller in Siberia, Ehrenberg, succeeded in keeping two luminous Infusoria of the Baltic alive for nearly two months at Berlin. I examined them with him in 1832; and saw them coruscate in a drop of sea-water on the darkened field of the microscope. When these luminous Infusoria (the largest of which was only ⅛ and the smallest from ¹⁄₄₈ to ¹⁄₉₆ of a of a Parisian line in length) were exhausted, and ceased to emit sparks, they would renew their flashing on being stimulated by the addition of acids or by the application of a little alcohol to the sea-water.

By repeatedly filtering fresh sea-water, Ehrenberg succeeded in procuring a fluid in which a large number of these light-emitting animalcules were accumulated.^[KH] This acute observer has found in the organs of the Photocharis which give off flashes of light (either voluntarily or when stimulated), a cellular structure of a gelatinous character in the interior, and which manifests some similarity with the electric organ of the Gymnotus and the Torpedo. “When the Photocharis is irritated, in each cirrus a kindling and a gleaming of separate sparks may be observed, which gradually increase and at length illuminate the whole cirrus; until the living flame runs also over the back of this nereid-like animalcule, making it appear under the microscope like a burning thread of sulphur with a greenish-yellow light. In the Oceania (Thaumanthias) hemisphærica, the number and position of the sparks correspond accurately, at the thickened base, with the larger cirri or organs which alternate with them, a circumstance that merits special attention. The manifestation of this wreath of fire is an act of vitality, and the whole development of light an organic vital process, which exhibits itself in Infusorial animals as a momentary spark of light, and is repeated after short intervals of rest.”^[KI]

The luminous animals of the ocean appear, from these conjectures, to prove the existence of a magneto-electric light-generating vital process in other classes of animals besides fishes, insects, mollusca, and acalephæ. Is the secretion of the luminous fluid which is effused in some animalcules, and which continues to shine for a long period without further influence of the living organism (as, for instance, in Lampyrides and Elaterides, in the German and Italian glow-worms, and in the South American Cucuyo of the sugar-cane), merely the consequence of the first electric discharge, or is it simply dependent on chemical composition? The luminosity of insects surrounded by air assuredly depends on physiological causes different from those which give rise to a luminous condition in aquatic animals, fishes, Medusæ, and Infusoria. The small Infusoria of the ocean, being surrounded by strata of salt-water which constitutes a powerful conducting medium, must be capable of an enormous electric tension of their flashing organs to enable them to shine so vividly in the water. They strike like the Torpedo, the Gymnotus, and the Electric Silurus of the Nile, through the stratum of water: whilst electric fishes which, in connection with the galvanic circuit, are capable of decomposing water, and of imparting magnetic power to steel needles. (as I showed more than half a century ago,^[KJ] and as John Davy has more recently confirmed,^[KK]) yield no indications of electricity through the smallest intervening stratum of flame.

The considerations which we have here developed render it probable that one and the same process operates, alike in the smallest living organisms invisible to the naked eye, in the contests of the serpent-like Gymnoti, in the flashing luminous Infusoria which impart such glorious brilliancy to the phosphorescence of the sea, in the thunder-cloud and in the terrestrial or polar light (the silent magnetic flashes), which, caused by an increased tension of the interior of the earth, are announced, for some hours previously, by the sudden variations of the magnetic needle.^[KL]

Sometimes one cannot, even with high magnifying powers, discover any animalcules in the luminous water; and yet, wherever a wave breaks in foam against a hard body, and, indeed, wherever water is violently agitated, flashes of light become visible. The cause of this phenomenon depends probably on the decomposing fibres of dead Mollusca, which are diffused in the greatest abundance throughout the water. If this luminous water be filtered through finely woven cloths, the fibres and membranes appear like separate luminous points. When we bathed at Cumana, in the gulf of Cariaco, and walked naked on the solitary beach in the beautiful evening air, parts of our bodies remained luminous from the bright fibres and organic membranes which adhered to the skin, nor did they lose this light for some minutes. If we consider the enormous quantity of Mollusca which animate all tropical seas, we can hardly wonder that sea-water should be luminous, even where no fibres can be visibly separated from it. From the endless subdivision of the masses of dead Dagysæ and Medusæ the whole ocean may, in fact, be regarded as a fluid containing gelatine, and, as such, luminous and of a nauseous taste; unfit for the use of man, but capable of affording nourishment to many species of fish. On rubbing a board with a portion of the Medusa hysocella, the surface thus rubbed recovers its phosphorescence when friction is applied by means of the dry finger. During my voyage to South America I occasionally placed a Medusa on a tin plate, and I then observed that if I struck the plate with another metallic substance the slightest vibrations of the tin were sufficient to cause the animal to emit light. How do the blow and the vibrations here act? Is the temperature momentarily augmented, or are new surfaces presented? or, again, does some gaseous matter such as phosphuretted hydrogen, exude in consequence of this impulse, and burn when it comes in contact with the oxygen of the atmosphere, or with that dissolved in the sea-water, and by which the respiration of the Mollusca is maintained? This light-exciting effect of the blow is most remarkable in a cross or sugar-loaf sea, (mer clapoteuse,) where the waves, clashing from opposite directions, rise in a conical form.

I have seen the ocean, in the tropics, luminous in the most opposite kinds of weather, but most strongly so before a storm, or in a sultry and hazy atmosphere with thick clouds. Heat and cold appear to exercise but little influence on this phenomenon, for, on the Bank of Newfoundland, the phosphorescence is frequently very brilliant in the severest winter. Occasionally, too, the sea will be highly luminous one night, and not at all so on the following, notwithstanding an apparent identity of external conditions. Does the atmosphere favour this development of light? or do all the differences observed during this phenomenon depend on the accidental circumstance of the sea being more or less impregnated, in some parts, with the gelatinous portions of mollusca? Perhaps these phosphorescent social animalcules only rise to the surface under certain conditions of the atmosphere. It has been asked, why our fresh-water swamps which are filled with polyps are not phosphorescent. It would appear that, both in animals and plants, a peculiar mixture of organic particles favours this development of light; thus, for instance, the wood of the willow is more frequently found to be luminous than that of the oak. In England, salt-water has been rendered luminous by mixing herring-brine with it; indeed, it will be easy for any one to convince himself by galvanic experiments, that the luminosity of living animals depends on nervous irritation. I have observed strong phosphorescence emitted from a dying Elater noctilucus, on touching the ganglion of its fore leg with zinc and silver. Medusæ also occasionally emit a stronger light at the moment the galvanic circuit is completed.^[KM]

ILLUSTRATIONS AND ADDITIONS.