Function, the office which an organ
is designed to perform, 29.
Galeopithecus, its facilities for
leaping, 93, 207.
Galerites, 233.
Gallinaceous,
mestic fowl, 190.
Gallop, 91.
Ganglions,

birds allied to the do-

scattered nervous mass-
es, from which nervous threads
arise, 46.
Ganoids, fishes having large, bony,
enamelled scales, mostly fossil, 20.
Gar-pike, 192.

Gasteropods, mollusks which crawl
by a flattened disk, or foot, on
the under part of the body, like
the snail, 22.
Gastric juice, 99.

Gavial, a crocodile, with a long,
slender head.

Gemmiparous reproduction, propa-
gation by budding, 156.

General properties of organized
bodies, 35.
Genus, 17.

Geographical distribution of ani-
mals, 186; conclusions, 207.
Geological succession of animals,
214.

Germ, the earliest manifestation of
the embryo, 42, 141.
Germinative disk, 133, 137, 141;
vesicle, 133, 137, 138; dot,137,138.
Gestation, the carrying of the young
before birth, 135.
Gills, 31, 120, 124.
Gizzard, 99.

Glacial period, 236.

Glands, 127; salivary, 127.

Globules of chyle, 100.
Glottis, 65.

Goniomya, 230.

Grallatores, birds with long legs for
wading, 20.

Grand-nurses of Cercaria, 162.
Granivorous, birds feeding on grain.
Grit, coarse sandstone, 216.
Gullet, 99.

| Herbivora, animals feeding on grass
and leaves, 20.

Hibernation, torpid state of ani-
mals during winter, 123.
Hippurites, 233.

Holothurians, soft sea-slugs, biche-
le-mar, 23.

Homogeneous, uniform in kind,126.
Homology, 30.

Humerus, the shoulder-bone, 81.
Hyaline matter, pure, like glass, 39.
Hydra, egg of, 133; propagation of,
156, 158.

Hydrogen, a gas which is the prin-
cipal constituent of water, 41.
Hydroids, a family of polyps, 23.

Ichthyosaurus, 229, 232.

Icterus Baltimore, nest of, 70.
Igneous, that have been acted upon
by fire, 215.
Iguanodon, 229.
Imbibition, 127.

Inanimate, destitute of life, 43.
| Incisor teeth, 106.

Incubation, hatching of eggs by the
mother, 136.

Infusoria, microscopic animals in-
habiting water, not yet fully ar-
ranged in their proper classes, 24,
32; motions of, 40; generation of
172.
Inocéramus, 232.

Inorganic,not made up of tissues,35.
Insalivation, 108.

Insects, number of, 27.
Insessores, perching birds, like
birds of prey, 20.
Instinct, 67, 69.

Intelligence, 67, 68.
Intercellular passages, 37.

Invertebrates, animals destitute of
a back-bone.

Iris, the colored part of the eye 40.
Isótelus, 225.

Jelly-fish. See Medusa.
Judgment, 68.

Kidneys, 130.

Labyrinthodon, 228.

Lacertans, animals of the lizard
tribe, 20.

Lacteals, vessels which take up the
nutriment, 100.

Lamellibranchiates, mollusks hav

their young, 19; number of, 27;
reign of, 222, 233.

Man, reign of, 222, 234; races of,
212; his twofold nature, 25.
Manatee, 206.

Manducata, insects furnished with
jaws, 21.

Marchantia polymorpha, reproduc-
tion of, 166.

Marl, earth principally composed

of decayed shells and corals, 216.
Marsupials, animals with a pouch
for carrying their young, as the
opossum; gestation of, 183.
Marsupites, 233.
Mastication, 101.
Mástodon, 236.

Matrix, the organ in which the em-
bryo is developed, 152.
Medulla oblongata, continuation of
the brain into the back-bone.
Medusa, jelly-like animals living in
the sea, 23; development of, 163;
digestive organs, 98; motion 80.
Megalobatrachus, 209.
Megalosaurus, 229.
Melocrinus amphòra, 224.
Memory, 68.

Menobránchus, 202, 209.
Menopòma, 202, 209.
Merganser, an aquatic bird allied to
the goose, 66, 193.
Metacarpus, the wrist, 83.
Metatarsus, 87.

Metamorphic rocks, 216, 174.
Metamorphosis, 149, 167; of the
silk-worm, 175; canker-worm,
176: duck-barnacle, 177; star-fish,
178; comatula, 179.

Micraster cor-anguinum, 232.
Miocene formation, 219.
Modern age, 222, 235.
Molar teeth, 106.

Molecules, very minute particles, 35.
Mollusks, soft animals of the snail
and oyster kind; heart of, 117;
liver of, 129; number of, 27; meta-
morphosis of, 179.

Monkey, teeth of, 107, 205.
Monóculus, mode of carrying eggs,
135; motion, 73: apparatus of, 73.
Moulting, the shedding of feathers,
hair, &c., 128.

Muscles, 73; disposition of, in in-
sects, 77; in fishes, 78; in birds,
79.

Muscular tissue, 39.

Myxine glutinosa, its eye, 55.

Natatores, birds with webbed feet
for swimming, 20.

Natica, tongue of, 102; heart of, 117.
Nautili, 22.

Neptunian rocks, 215.

Nereis, jaws of, 102; gills of, 81;
eye, 53.

Nervous system, 44; in mammals,
45; in articulates, 46; in crusta-
ceans, 46; in radiates, 47.
Nervous tissue, 39.

Nest of Baltimore oriole, 70; of tai-
lor bird, 70; of Ploceus, 71.
Nomenclature, the naming of ob-
jects and their classes, family, &c.
Nostrils, 60.

Peduncle cr Pedicle, a slender stem.
Pelvis, the cavity formed by the
hip bones, 87.

Pentácrinus, 231; metamorphosis
of, 180.

Perception, 67.

Perchers, a class of birds, 20.
Peripheric, exterior surface, 152.
Peristaltic motion, 100.
Petrifactions, 215.
Phalanges, 83.

Pigment, a coloring substance, 40.
Pituitary membrane, 61.
Placenta, the organ by which the
embryo of mammals is attached
to the mother, 152.

Placoids, fishes with a rough skin,
like the shark or skate, 20.
Planaria, its digestive apparatus,
98; an eye of, 53.

Plant-lice. See Aphides.

Plants compared with animals, 41.
Platynotus, 225.

Pleiocene formation, 219.
Plesiosaurus, 229, 232.
Pleurotomària, 233.

Ploceus Philippinus, nest of, 70.
Plutonic rocks, 215.

Podurella, mode of leaping, 92; em-
bryo of, 144; egg of, 133.
Polyps, a small animal fixed at one
end, with numerous flexible feel-
ers at the other, 27, 53; repro-
duction of, 158.

Prehension, act of grasping, 109.
Primary age, 222.
Primitive stripe, 143.
Progression, 88, 90.

Proligerous, the part of the egg
bearing the embryo, 141.
Proteus, 209.

Protosáurus, 228.

Protractile, capable of being ex-
tended.
Pterichthys, 226.

Pterocoma pinnata, 231.

Pterodactylus, 230.

Pteropods, mollusks with wing-like
expansions for swimming, 22.
Pulmonary, relating to the lungs,
116.
Pulmonates,

respire air, 22.

Pupil, 40.

mollusks

Pyrula, egg-cases of, 135.

which

Quadrumanous, four-handed, 201

40.

Radiata. animals whose organs ra-
diate from a centre, 23, 27.
Radius, one of the bones of the
arm, 83.

Reign of fishes; of man, 235; of
mammals, 233; of reptiles, 238.
Relation, functions of, 44.
Reproduction, 131; peculiar modes,
156.

Reptiles, number of, 27; reign of,
222, 227.
Respiration, 97, 118.

Rete mucosum, 129; retina, 49.
Retractile, that may be drawn
back, 84.

Rhizodonts, 20; of the trias, 228.
Rhizopods, 22.

Rocks, classification of, 215; defi-
nition of, 215.
Rodents, quadrupeds with teeth for
gnawing, 107.

Rotifers, jaws of, 103; eggs of, 172.
Ruminants, quadrupeds which chew
the cud, 107.
Running, 91.

Rytina Stélleri, 210.

Salènia, 233.

Silex, flinty rock.

Siliceous, made of nint.
Silk-worm, metamorphosis of, 175.
Silurian rocks, lower, 217; upper,
218.

Sinuous, bending in and out, 22.
Siphonophori, 23.
Siren, 209.
Skeleton, 74, 77.

Skin, structure of, 128.
Smell, 60.

Species, constancy of, 67; definition
of, 17, 159.
Spinal marrow,
Spondyli, 233.

45.

Sponges not animal, 41.
Spontaneous generation, 171.
Spores, the germs of sea-weeds,
ferns, &c., 170.
Standing, 88.
Stapes, 57.

Star-fish, metamorphoses of, 178;
eye of, 53; mode of progression,
81; reproduction of parts, 126.
Stigmata, openings in insects for
the admission of air, 118.
Stomach, 97.

Stratified rocks, 215.
Stratum, a layer.

Strobila, 164, 169.

Structure of the earth's crust, 214.
Sturgeon, compared with white-
fish, 180.

Suctoria, insects taking their food
by suction, 21.
Swimming, 93.

Sylvia sutoria, nest of, 70.
Systole, the contraction of the heart
to force out the blood, 115.

Tape-worm, reproduction of, 140.
Tapir, 204, 234.

Tarsus, the ancle, 87.
Taste, 62.
Teeth, 104.

Temperate faunas, 198.

Temporal, relating to the temples,
104.

Tentacle, the horn-like organs on
the head of mollusks, usually
bearing the eyes, 52.
Terebratula, 230.

Tertiary age, 222, 233.

Tertiary formation, lower, 218; up
per, 219.

Tubulibranchiates, 21.

Ventricle, a cavity of the heart, 115.
Vermicular, 100.

Vertebra, a joint of the back-bone,
46, 77.

Vertebrate, having a back-bone, 19,
27.

Vertical, in a perpendicular direc-
tion, 48

Vesicle, a small membranous bag,
37.

Vestibule, a porch; the entrance to
one of the cavities of the ear, 58.
Vibratile, moving to and fro, 112.
Viscera, 159.

Vitelline membrane, 138.
Vitellus, 137.

Vitreous humor, 50.

Viviparous, producing living young,
131.

Vocal cords, 65.

Voice, 64.

Voluntary, under control of the will,

43.

covering, 159.

Turrilites, 232.

Tympanum, a drum; the membrane
separating the internal and exter-
nal ear, 57.

Type, an ideal image, 18.

Walking, 90.
Wapiti, 211.

Warm-blooded animals, 122.
Water-tubes of aquatic animals, 123.
Whale, fans of, 104.

Whales, mode of swimming, 94.

83.

Ultimate, final.

Univalve, having a single shell, like
the snail, 27.

Vascular, composed of vessels, 129.
Vegetative life, 44, 96; layer, 142.
Veins, 113.

Windpipe, 119.

Worms, 21; eye of, 53.

Zoology, its sphere, 25.

Zoophytes, animals of a very low
type, mostly fixed to the ground.
of a plant-like form.