Pictures, charts, lantern slides, and books showing cow, sheep, hog, goat, horse, etc. Diagram of skeleton.
Since it is impossible to have living ungulates in the laboratory, this study should be supplemented by trips to a museum and to a zoölogical garden. Observe also such hoofed animals as may be common in your neighborhood. Use your camera and make "snapshots," showing characteristic attitudes of these animals.
Note.—Answer the following questions for one or more of the following: The cow, sheep, goat, hog, and horse. If desired, the questions may be answered in the form of a table.
In a short thesis summarize the facts you have found out about ungulates, using the following outline:—
The pupil is expected to study carefully the account of Eohippus or Hyracotherium in his text or any other available reference book, and to supplement that work and this brief sketch with original observations upon horses on the street, at a local store, or wherever possible or convenient.
From the early horses which migrated from North America there arose in Asia and Africa the ass, famous in the history of early civilization and still used in some localities as beasts of burden or for the breeding of mules, which are the crosses between ass and horse. There also arose the zebra and the most primitive of modern horses, Przewalskii's horse, a wild pony of western China, about forty inches high and almost identical with the drawings of the horse made by early man, 30,000 years ago. Doubtless the modern ponies of Ireland, Iceland, and Shetland are descendants of the original Przewalskii type and not, as is often claimed, true horses stunted by rigors of climate and scant fare.
The horse is characterized largely by the presence of a lock of hair between the ears, a full mane and tail, small ears, large hoofs, and peculiar neigh. The ass has no forelock, a scanty mane and tail, long ears, small hoofs, and a distinct bray.
By means of various crusades and raids, the modern horse was introduced into Europe from Asia, where it is clearly traced in history to the reign of King Solomon. Here, in Europe, because of local conditions and demands, it assumed differing type forms. The roadster type is closest to the Arabian in character. The draft or heavy type was bred in western Europe when heavy armor came into use for rider and horse, and the coach or carriage type was developed when armor was abandoned for gunpowder. Finally explorers and colonists brought the horse back to America, its original home.
The various types and varieties may be briefly described.
A. The draft type has short legs, short neck, large round body, and ranges in weight from 1400 pounds to 2000 pounds.
Varieties:—
B. The coach or carriage type has legs and neck of medium length, a body full-chested but not blocky, and a weight varying from 1150 pounds to 1400 pounds.
Varieties:—
C. The roadster type is long and lean of limb and body, and averages about 1100 pounds in weight.
Varieties:—
The horse is very similar to man in its physical and mental character, being subject to the same ailments and treatment and having the same impulses of affection, hatred, fear, jealousy, obedience, willfulness, memory, and perhaps reason. It is of all animals most careful in its eating and drinking; because its stomach is small, the food should not be bulky but concentrated, grain forming a goodly portion of the ration.
Perhaps the most important point in the structure of the horse is the form of the leg and foot. The shoulder should slope slightly backward and the pastern joint, immediately above the hoof, slightly backward. The hips, or "quarters," should slope downward somewhat, and the hock should be comparatively wide to afford ample leverage for the pulling muscles. The legs should be straight as pillars when seen from front or rear. The outer walls of the hoof support most of the weight though the frog should normally touch the ground. In nature the hoof wears away properly of itself, but the shod hoof needs regular trimming attention, while the frog must not be trimmed, for it is the soft growing part that nourishes the hoof. In this treatment the foot is comparable with the human finger and finger nail.
If access to a living animal is impossible or inconvenient, the pupil may use reference book or pictures for most of these points. A measuring tape or ruler should be at hand, and the assistance of an experienced person is a valuable aid. If several horses are studied, they should be distinguished by name or number.
Record the color, condition, weight, and height of the horse at the shoulder. (Height is given in "hands," a hand being the breadth of the palm, or 4 inches.) Note the slope of the shoulder, of the back and the hips, the general form of the head and neck, and the facial expression. Find the chestnuts, warty growths on the inside of each leg. Examine the foot, finding the V-shaped frog in the center, surrounded by the horny hoof.
Find the pulse by passing the fingers downward from the upper curve of the neck, along the inside of the jaw; count the pulse. Notice the position and motion of the ears with their lining of hair, and the position of the eyes, the form of the pupil, and the probable range of vision. Watch the horse use its lips, and examine the mouth and teeth, finding the grinding teeth far back in the mouth, the incisors in front, and the space where the canines are missing.
The male may have canines in the upper jaw.
On the surfaces of the incisors are the depressions, or "cups," by means of which age is determined.
At six years the cups leave the lower center teeth; at seven the adjoining teeth; and at eight, the outer lower teeth. At nine years they leave the upper center incisors; at ten, the adjoining teeth; and at eleven, the outer teeth above. At the age of ten years a spot appears in the outer upper incisors, at fifteen years the groove has worn to the center of the tooth, and at twenty-one years the groove is worn to the bottom of the tooth.
Prepared skeletons of an amphibian, a reptile, a bird, another mammal, and man. If any of these be lacking, lantern-slide illustrations may be used in a partially darkened room.
Having studied the frog's skeleton in detail, the student can readily compare each of these types with it. Compare in a very general way the skulls, the girdles, and the limbs; their form and use. Note variations in the form and number of the vertebræ and the number of the ribs.
Slides or diagrams, showing a dividing amœba, a dividing paramecium, a dividing vorticella, reproduction in some form of sporozoa, budding hydra, gemmules of spongilla, and some species of worm as Dero or Nereis in the process of dividing.
Note.—Refer to your notes, if the animals mentioned in these exercises have been already studied. This exercise may be largely review.
Study the methods of reproduction in the specimens or diagrams before you. Determine first, in what respects the methods of reproduction are similar in all; second, in what respects there is a variation.
Slides or diagrams showing hydra and sponge reproducing sexually. Conjugating paramecia, fertilized and unfertilized starfish eggs.
Identify the reproductive organs or gonads of the hydra. These are slight swellings on the surface. The one nearer to the mouth end is the spermary and that near the attached end is the ovary.
Summary of important points in the study of methods of reproduction:—
Hen's eggs, hydrochloric acid.
Boil an egg at least ten minutes in water deep enough to cover it. Note which side is uppermost and mark this part of the shell for reference. Remove the egg and pick away the shell from about half the egg, leaving the shell on that portion which was underneath when placed in water. With a sharp knife remove this half of the egg. Note the thickness of the shell. Test its composition (use hydrochloric acid). Find the membrane lining the shell and note that at one end it separates into two parts to inclose an air space.
Break an uncooked egg in a saucer. Note the germ spot. Note also the difference in the consistency of the "white" (albumen) and yellow portion ("yolk").
Weigh a fresh egg, place it in a dry atmosphere for a week, and weigh it again. Record result. Why may eggs be kept a long time perfectly fresh if coated with paraffin or if put in "water glass"?
Slides or diagrams, showing various stages in the development of some animal through the gastrula stage.
Some specimens of the larvæ and pupæ of the mosquito, ordinarily known as wrigglers. Either specimens or diagrams of egg packets should also be provided. Mounted specimens of adult of both sexes.
The eggs, caterpillars, pupæ, cocoons, and adult of some moth or similar stages of a butterfly.
How does the number of prolegs differ from that of the caterpillar in the case of the grub? maggot? currant worm?
Describe the cocoons of tussock moth, clothes moth, leaf roller.
How do the antennæ of moths and butterflies vary?
An incubator, a brooder, a setting of eggs.
Read carefully the directions for setting up and regulating the incubator. Remember that the temperature should average 103 degrees and should not vary more than two or three degrees above or below this. Candle the eggs from time to time and note difference in appearance, as development proceeds, especially as to transparency and size of the air space. An egg that is transparent after ten days is probably infertile and should be removed. Eggs which are developing properly will show from this time on a well developed air space, and will be quite opaque. The veins often give a spider-web appearance.
Twice each day remove the tray of eggs and allow to cool slightly. Once a day the eggs should be turned before the tray is returned to the incubator.
Books and diagrams showing as many methods for the care of young as possible.
Either pictures or specimens of the different breeds of fowl.
Under the term poultry are included chickens as well as turkeys, pigeons, ducks, geese, etc. Chickens are most generally raised, since they do not require such special conditions as the others. In this exercise only this form of poultry is considered.
The hen has been domesticated from prehistoric times, being probably derived from the so-called jungle fowl of India (Gallus bankiva), which is still to be found in its native habitat. Through constant attempts to improve the domestic fowl along the lines of greater egg-production, size, etc., there have been developed a great many different breeds of fowl. These may be divided into seven groups, as follows:
The American Class includes fowls raised both for egg-production and for eating. It includes the following well-known breeds: the Plymouth Rocks, the Wyandottes, the Rhode Island Reds, and the less-known breeds of Javas, Dominiques, and Jersey Blues. These all lay good-sized brown eggs, are good winter layers, and stand confinement well. The standard weight varies from six and one half pounds to seven and one half pounds for the hen, and from eight and one half pounds to nine and one half pounds for the cock, the Plymouth Rocks being the heaviest of the breeds.
There are three principal varieties of Plymouth Rocks—the Barred Rocks, with grayish-white plumage regularly crossed with bars of blue-black, the White Rocks, and the Buff Rocks. All have single upright combs, which, with the wattles and the ear lobes, are bright red, a large bright eye, and yellow legs.
There are also three principal varieties of Wyandottes. The Silver-laced Wyandotte has a silvery-white plumage, with black markings in various parts of the body. The Golden Wyandotte is similar in its markings, but has yellow where the Silver-laced has white. The White Wyandotte is pure white. All have rose combs, red ear lobes, and yellow legs. They are on the average about a pound lighter than the Plymouth Rocks.
The Rhode Island Reds are a much more recent breed that has of late become very popular. They are of a reddish-brown color, about the weight of the Wyandotte, with yellow legs. There are both single combed and rose combed varieties.
The Asiatic Class includes those breeds raised chiefly for the table. The Brahmas, Cochins, and Langshans are the chief breeds. They are considerably heavier than other breeds, and are specially characterized by the feathers on the legs and feet. They all lay brown eggs, and are in many cases good layers.
The Brahmas include two principal varieties, the light and the dark. The general color is black and white, and they have yellow legs, red wattles, ear lobes, and comb, the latter being of the kind called a pea-comb, which is of small size in the cock.
There are four varieties of Cochins, the Buff being much more raised than the Partridge, the White, or the Black. The Partridge somewhat resembles a dark Brahma, but has red and brown plumage. Cochins have single combs, yellow legs, and a general fluffy character to the plumage, that of saddle and hackle meeting, thus giving a characteristic appearance to these fowls. The eggs are not quite so large as the other two breeds of this class.
The Langshans are smaller and more active than the two breeds just described. They have black legs, the feet are not so heavily feathered, and in general these fowls are much less awkward in appearance. There are two varieties, the White and the Black.
The Mediterranean Class includes those breeds raised chiefly because of their great egg-production. They are active birds, often troublesome because of their ability to fly over high enclosures, so that when kept in the city it is usually necessary to clip one wing. They are not so good winter layers as a rule, but are non-setters. They all lay white eggs. The chief breeds included are the Leghorns, the Minorcas, and the Black Spanish.
The Leghorns—the most popular of these breeds—include two chief varieties, the Brown and the White. The comb is most commonly single, falling to one side in the hen, the wattles long and pendulous, the ear lobes white, and the legs yellow.
The Minorcas are glossy black in color, with a large drooping comb in the hen, and long, thin, pendulous wattle. They lay a very large egg.
The Black Spanish resemble the Minorcas, but are distinguished by the white face and cheeks and the white on the inner edge of the wattles.
The English Class includes the Orpingtons and the Dorkings. The Dorkings are one of the oldest breeds of fowl, and sufficiently identified by the presence of a fifth toe. There are three varieties—the White, the Silver-gray, and the Colored. The White Dorking has a rose comb; the Silver-gray has a single comb and silvery-gray plumage with black markings, the hen having a salmon-colored breast; the Colored Dorkings have sometimes single and sometimes rose combs, the plumage of the cock being black and straw-colored and that of the hen being black and gray with the breast salmon marked with black.
The Orpingtons are short legged, with close plumage. They are of large size, the hens being from seven to eight pounds and the cocks from nine to ten pounds. There are three varieties—the black, the buff, and the white. The black, except for shape, might be mistaken for a Minorca, but has red ear lobes and black shanks. The Orpingtons have the reputation of maturing early, some strains being known to lay when four months old.
The Dutch Class includes the Red-caps, the Campines, and the various varieties of the Hamburgs—of which there are six: the Golden Spangled, the Silver Spangled, the Golden Penciled, the Silver Penciled, the Black and the White. They are all good layers and non-setters, "but lay a small egg, white in color. They are readily recognized by their peculiar rose comb with its long, spikelike projection in the back, their red face, white ear lobes, and bluish legs. The prevailing color of the golden varieties is a reddish bay marked with black and of the silver varieties white marked with black. The cock usually has more dark markings than the hen.
The Red-caps are large fowl with a red and black plumage. The comb is similar to the Hamburg's but larger, and the ear lobes are red.
The Campines resemble the Hamburgs, but have a single comb.
The French Class includes the Houdans, the Crevecœurs, and the La Fleche. The Houdans are mottled black and white with pinkish white legs, with a fifth toe like the Dorkings, and are easily recognized by their peculiar crest.
The other breeds of fowl, like the crested Polish, Bantams, and game fowl, have less interest for the poultry raiser, though often seen in exhibitions and poultry shows.
To sum up, we may group all these breeds according to their value into (1) the egg breeds, including the Leghorn, Minorca, Spanish, and Red-cap; (2) the meat breeds, including the Brahmas, Cochins, and Langshans; (3) the general purpose breeds, including the Plymouth Rocks, Wyandottes, Rhode Island Reds, Dorkings, and Orpingtons; and (4) the fancy breeds, including the Polish, Bantams, Games, etc.
American Standard of Perfection, an illustrated volume published by the American Poultry Association, indicating the desirable points of each recognized breed of fowl.
Ab do' men, (1) the hinder portion of the body of an invertebrate; (2) of higher animals, the region or cavity containing the stomach, intestine, etc.
Al bu' men, (1) a proteid substance; (2) "white of egg."
A' nal, pertaining to the anus, or hinder opening of the intestine.
Anal fin, a ventral median fin of fishes, just back of the anus.
Animal Communities, associations of many animals of the same species.
An ten' na, a segmented sensory appendage on the head of an arthropod.
An ten' nule, a small antenna.
An te' ri or, farther forward, in front of; at the head or forward end.
A or' ta, a large artery arising at the heart and forming the trunk of the arterial system.
Ap' er ture, an opening.
Ap pend' age, a projection from the body, usually one of a pair.
Ar throp' o da, a group of animals with a segmented trunk and paired, segmented appendages.
Ar ti o dac' tyl, an ungulate with an even number of toes.
A sex' u al, without sex.
Au' di to ry, pertaining to hearing.
Barb, one of the lateral outgrowths of the shaft of a feather, forming the vane.
Barb ule, a small outgrowth of the barb of a feather.
Bi lat' er al sym' me try, having the right and left sides mirror images one of the other.
Body cavity, the space between the body wall and the alimentary canal.
Body-wall, the outer wall in bodies of the many-celled animals.
Budding, a form of fission in which a cell or portion of the body forms a small protuberance or bud, which is then cut off from the parent and forms a new individual.
Canals, channels through the body-walls of sponges.
Car' a pace, the shell which covers a portion or all of the cephalo-thorax in crustaceans.
Car' di nal, pertaining to a cardo or hinge.
Car niv' or ous, flesh-eating.
Car ot' id, a large artery which supplies the brain and head with blood.
Car' pal, a bone of the wrist.
Cat' er pil lar, the larva of a butterfly or moth.
Caud al, pertaining to the tail.
Cell, the smallest living unit.
Cell-wall, the lifeless membrane surrounding many cells, secreted by the protoplasm.
Central cavity, the cavity surrounded by the body-wall in the simpler many-celled animals, as in the sponges.
Ceph a lop' o da, the class to which the squid, octopus, nautilus, etc., belong.
Ceph' al o-tho' rax, the division of the body formed by the fused head and thorax in many arthropoda.
Cer' vi cal groove, the groove marking the place of union when head and thorax are merged into a cephalo-thorax.
Cha la' za, one of the spiral masses of albumen found at the two ends of a bird's egg.
Che' li peds, the large claws in many crustaceans.
Chor-date, animals with a notochord, present throughout life or disappearing.
Chro mat' o phore, color body.
Chrys' a lis, the pupa stage of a butterfly.
Cil' i um (pl. cilia), a minute vibrating hair on the surface of many cells.
Co coon', the envelope spun by certain larval insects in which they are inclosed during the pupa stage. A similar structure, as the egg-case of spiders, earthworms, etc.
Cœ' cum (se' kum), a blind pouch or bag; a sac open at one end.
Cœ len te ra' ta, rather simple, sac-like animals with nettle cells in the body walls.
Co le op' te ra, beetles.
Col' o ny, a group of animals of the same kind found in one locality, usually related to each other and often actually connected.
Com men' sal ism, an association of two animals, not mutually helpful, but without injury to either.
Com pound eye, an eye made up of many simple eyes or eye elements.
Com pressed', narrower from side to side than from dorsal to ventral surface.
Con ju ga' tion, a process occurring in some one-celled animals, preceding reproduction. In this process two animals unite temporarily and exchange nuclear substance, or in some forms the two cells fuse into one. After this exchange or fusion fission occurs, usually more rapidly than before.
Contracting or pulsating vacuoles, small, clear spots in a cell, filled with a watery fluid. In the living animal these alternately disappear and then reappear.
Co' nus ar te ri o' sus, a cone-shaped artery connected with the ventricle of the heart.
Cov' ert, a feather overlying the base of the large feathers of the wing or tail.
Cra' ni um, the skull, particularly that part of it inclosing the brain.
Crop, an enlarged portion of the esophagus.
Cross fertilization, a form of fertilization in which the male and female elements are produced by different individuals.
Crus ta' ce a, aquatic, gill-bearing arthropods, with two pairs of antennæ.
Cu' ti cle, the thin outer skin.
Cy' to plasm, the portion of the protoplasm of a cell which is outside of the nucleus, less dense than the nucleus and usually taking a lighter stain.
Den' ta ry, the terminal portion or bone of the lower jaw of vertebrates lower than mammals, containing all or most of the teeth.
Di a phragm, a muscular partition separating the abdomen and thorax, in mammals.
Dig' i ti grade, walking on the toes.
Di œ' cious, reproductive organs in different individuals.
Dip' te ra, insects with two wings, including flies, mosquitoes, etc.
Dis' tal end, the free end of any object which is attached by one end.
Dor' sal surface, the upper surface; the back.
Du' o de' num, the first portion of the small intestine.
Ec' to derm cells, cells covering the outside of sponges and some other simple animals.
Egg cell, the large, non-motile reproductive cell, with which a sperm cell fuses.
Em bry on' ic, development within the egg or in the body of the mother.
En' do derm cells, cells lining inner cavities in the many-celled animals. As a rule they have cilia or flagella.
E soph' a gus, the portion of the alimentary canal connecting the mouth (or the pharynx) with the stomach.
Eu sta' chi an (eu sta' kian) tube, a passage between the pharynx and the middle ear.
Ex ha' lent, flowing or moving away from the body.
Ex' o skel' e ton, an external skeleton.
Eye stalk, an appendage which bears an eye on its free end.
Fe' mur, (1) the thigh bone; (2) the third joint of an insect's leg.
Fer ti li za' tion, the fusion of male and female elements in reproduction.
Fi' bers, flexible threads; fibers of a horny material are found in the walls of many of the sponges.
Fib' u la, the outer of the two long bones of the lower leg.
Fin, a paddle-like structure for swimming.
Fin-rays, the framework of the fins of fishes.
Fis' sion, a method of reproduction used in all cells, by which a cell divides itself into two, usually through the center. See also Conjugation and Budding.
Fla gel' lum (pl. flagella), vibrating hairs larger than cilia and less numerous.
Food-balls, bits of food inside the cells of many one-celled animals, usually showing through the walls.
Food-vacuole, a small drop of water containing digestive material and a food-ball.
Fo ra' men, an opening or short passage.
Gall-bladder, a membranous sac for the storage of gall, or bile, at the lower edge of the liver (syn. "bile sac").
Gas ter op' o da, the class to which the snail belongs.
Ge' nus (pl. genera), a group of closely related species.
Germ-spot, the region in the bird's egg in which development first takes place.
Gill, an apparatus for breathing the air dissolved in water.
Gill-cham' ber, a pocket or cavity covered by a flap, in which the gills lie.
Gir' dle, the name applied to the smooth band often occurring near the anterior end of an earthworm.
Giz' zard, a portion of the alimentary canal with especially thickened muscular walls.
Glot' tis, the opening between the vocal cords, or the mouth of the windpipe.
Gre ga' ri ous, associations of animals with little division of labor; gathering in flocks, herds, etc.
Gullet, the inner end of the oral groove.
He mip' te ra, insects with a piercing organ for sucking their food, Bugs.
He pat' ic, pertaining to the liver.
Her biv' o rous, plant-eating.
Hock, the joint of the hind leg situated between the tibia and tarsus, corresponding to the ankle in man.
Hu' me rus, the long bone of the upper part of the arm or fore limb.
Hy men op' te ra, order of insects to which belong bees, ants, and wasps.
Ich neu' mon (ic nu' mon), an insect that deposits its eggs upon or in other insects, upon which its larvæ will feed.
In ha' lent, flowing or moving toward the body.
In ha' lent pores, the outer ends of the canals in the body-walls of sponges.
Ink-sac, a defensive structure found in the squid.
Ju' gu lar, pertaining to the throat.
La' bi um, lower lip.
La' brum, upper lip.
La mell' i branch i a' ta, the class to which the clam, oyster, etc., belong; bivalves, sometimes called pelecypoda.
Lar' va, (1) the early form of an animal when it is unlike the parent, or undergoes a metamorphosis; (2) the first stage of postembryonic development.
Lat' er al, (1) situated to one side of the median plane; (2) situated in the region of the hinge in a bivalve shell.
Lep i dop' te ra, butterflies and moths.
Lig' a ment, a strong band or cord binding two structures together.
Lin' gual, pertaining to the tongue.
Lip, any structure that bounds an orifice.
Mam' mal, vertebrates with a covering of hair or fur.
Man' di ble, a jaw or a jaw-like mouth-part.
Man' tle, folds of skin covering the body of a bivalve.
Masking, the covering of an animal by some object so as to hide its identity.
Max il' læ, the appendages just back of the mandibles in arthropods.
Max' il la ry, pertaining to or situated near the jaw.
Max il' li peds, the appendages back of the maxillæ in crustaceans.
Me' di an, pertaining to the middle.
Mes o gle' a, a non-cellular layer between ectoderm and endoderm cells.
Mes o tho' rax, the middle division of the thorax.
Met a car' pal, one of the bones between the wrist (carpus) and the fingers (phalanges).
Met a mor' pho sis, the series of changes which take place in the development of some animals after they are hatched.
Met a tar' sal, one of the bones of the metatarsus, between the ankle and the toes.
Met a tho' rax, the most posterior region of the thorax.
Mi cro nu' cle us, see Nucleolus.
Mimicry, a method of protection due to the resemblance of an unprotected to a well-protected animal.
Mol lus' ca, the branch of animals to which clams, snails, etc., belong.
Mo nœ' cious, reproductive organs in different regions of the same individual.
Mouth, the anterior opening into the digestive cavity.
Neph rid' i um (pl. neph rid' i a), a tubule functioning as a kidney in some of the worms.
Net' tle cells, the stinging cells found in the cœlenterates.
Noc tur' nal, pertaining to night.
Nu cle' o lus (pl. nucleoli), a very small, dense, dark-staining body, either within the nucleus or near it. In the latter case it is often called the paranucleus or micronucleus.
Nu' cle us (pl. nuclei), a dense bit of protoplasm usually near the center of a cell, often staining dark.
O cel' lus, a simple eye.
Om niv' o rous, eating or living upon food of all kinds.
O per' cu lum, a lid or cover.
O' ral, pertaining to the mouth.
Oral groove, a funnel-shaped groove in one side of some one-celled animals conducting food to the mouth.
Or' der, a term in classification used to designate a group of genera.
Or thop' ter a, the order to which locusts, grasshoppers, etc., belong.
Os' cu lum (pl. oscula), the large opening from the central cavity in sponges.
Os mo' sis, the process by which fluids of different densities become equally diffused when separated by an organic membrane or by a porous structure.
Os' ti a (sing. ostium), the inner ends of the canals in the body-walls of sponges.
O' va ry, the organ in which the egg cells are developed.
O vi pos' i tors, organs used to deposit eggs.
Pal' li al, a line connecting the two muscle scars in a bivalve shell.
Palp, (1) a jointed finger-like structure on the oral appendages of arthropods; (2) oral appendages found in mollusca.
Pan' cre as, one of the glands of the digestive system.
Par a nu' cle us, see Nucleolus.
Par' a si tism, an association of two animals, one living at the expense of the other.
Pec' to ral, (1) pertaining to the thorax or breast; (2) the anterior of the paired fins of fishes.
Pelvic, (1) pertaining to the pelvis; (2) the posterior paired fins of fishes.
Pen, a remnant of exoskeleton found in the squid.
Per i car' di um, a membranous bag surrounding the heart.
Per is so dac' tyl, ungulates with an odd number of toes.
Per' i to ne' um, a membrane that lines the body cavity.
Pha' lanx (pl. phalanges), one of the bones of the fingers or toes.
Phar' ynx, the region of the alimentary canal just back of the mouth cavity.
Pigment, a substance which gives color to an object.
Plan' ti grade, walking on the soles of the feet; flat-footed.
Pol' len bas ket, the flattened hairy tibia of the hind legs of honey bees, used for carrying pollen.
Pol' lin na tion, the transfer of pollen from the anther of a flower to the stigma.
Polyp, any radially symmetrical animal, but usually an individual in a connected colony.
Po rif' e ra, the sponges, distinguished by the canals which perforate the body wall.
Post em bry on' ic, development after birth or hatching.
Pos te' ri or, situated behind or toward the hinder part.
Pro bos' cis, a prolonged, flexible snout or a tubular structure, protruding from the head.
Pro' leg, an unsegmented appendage found in the larvæ of some insects.
Protective resemblance, a method of protection due to the resemblance of an animal to its background.
Pro tho' rax, the most anterior division of the thorax.
Pro' to plasm, the living material composing the cell; the physical basis of life.
Pro to zo' a (sing. protozoön), animals of one cell, existing alone or in loose colonies.
Prox' i mal end, the attached end of anything which has also a free end.
Pulsating vacuoles, see Contracting vacuoles.
Pu' pa, the stage in the development of an insect immediately preceding the adult.
Quill, one of the large, stiff, strong flight feathers or tail feathers of a bird; the hollow, basal part of a feather; a large, hollow, sharp spine.
Ra' di al sym' me try, having the organs or parts arranged symmetrically around a center.