INDEX

A Abiogenesis, 26 Accipenser, 234 Abortive ova, 55 Achromatin, 42 Achromin, 42 Acœla, 221 Acoustic nerve, the, 289, 290 Acquired characters, inheritance of, 349 Acrania, the, 182 Acroganglion, the, 268, 275 Adam’s apple, the, 184 Adapida, 257 Adaptation, 3, 5, 27 After-birth, the, 167 Agassiz, L., 34 Age of life, 200 Alimentary canal, evolution of the, 13, 14, 133, 308–17 — — structure of the, 169, 308–10 Allantoic circulation, the, 171 Allantois, development of the, 166 Allmann, 20 Amblystoma, 243 Amitotic cleavage, 40 Ammoconida, 217 Ammolynthus, 217 Amnion, the, 115 — formation of the, 134, 244 Amniotic fluid, the, 134 Amœba, the, 47–9, 210 Amphibia, the, 239 Amphichœrus, 221 Amphigastrula, 80 Amphioxus, the, 105, 181–95 — circulation of the, 184 — cœlomation of the, 95 — embryology of the, 191–95 — structure of the, 183–88 Amphirhina, 230 Anamnia, the, 115 Anatomy, comparative, 208 Animalculists, 12 Animal layer, the, 16 Annelids, the, 142, 219 Annelid theory, the, 142 Anomodontia, 246 Ant, intelligence of the, 353 Anthropithecus, 174, 262 Anthropogeny, 1 Anthropoid apes, the, 166, 173, 262 Anthropology, 1, 35 Anthropozoic period, 203 Antimera, 107 Anura, 243 Anus, the, 317 Anus, formation of the, 139 Aorta, the, 327 — development of the, 170 Ape and man, 157, 164, 261, 307, 351 Ape-man, the, 263 Apes, the, 257–60 Aphanocapsa, 210 Aphanostomum, 221 Appendicaria, 197 Appendix vermiformis, the, 32 Aquatic life, early prevalence of, 235 Ararat, Mount, 24 Archenteron, 64, 74 Archeolithic age, 203 Archicaryon, 55 Archicrania, 230 Archigastrula, 65, 193 Archiprimas, 263 Arctopitheca, 261 Area, the germinative, 121 Aristotle, 9 Arm, structure of the, 306 Arrow-worm, the, 191 Arterial arches, the, 325–26 — cone, the, 324 Arteries, evolution of the, 170, 323–24 Articulates, the, 142, 219 — skeleton of the, 294 Articulation, 141–42 Aryo-Romanic languages, the, 203 Ascidia, the, 181, 188–90 — embryology of the, 196–98 Ascula, 217 Asexual reproduction, 51 Atlas, the, 247 Atrium, the, 183, 185 — (heart), the, 326 Auditory nerve, the, 289, 290 Auricles of the heart, 325 Autolemures, 257 Axolotl, the, 243 B Bacteria, 38, 210 Baer, K. E. von, 15–17 Balanoglossus, 226 Balfour, F., 21 Batrachia, 241 Bdellostoma Stouti, 78 Bee, generation of the, 9 Beyschlag, W., on evolution, 50 Bilateral symmetry, 66 — — origin of, 221 Bimana, 258 Biogenetic law, the, 2, 21, 23, 179, 349 Biogeny, 2 Bionomy, 33 Bird, evolution of the, 245 — ovum of the, 44–6, 80–1 Bischoff, W., 17 Bladder, evolution of the, 244, 339 Blastæa, the, 206, 213 Blastocœl, the, 62, 74 Blastocrene, the, 99 Blastocystis, the, 62, 119, 120 Blastoderm, the, 62 Blastodermic vesicle, the, 119 Blastoporus, the, 64 Blastosphere, the, 62, 119 Blastula, the, 62, 74 — the mammal, 119 Blood, importance of the, 318 — recent experiments in mixture of, 172 — structure of the, 319 Blood-cells, the, 319 Blood-vessels, the, 318–25 — development of the, 168 — of the vertebrate, 110 — origin of the, 320–21 Boniface VIII, Bull of, 10 Bonnet, 13 Borneo nosed-ape, the, 164 Boveri, Theodor, 185 Brachytarsi, 257 Brain and mind, 278, 354–56 — evolution of the, 8, 275–80 — in the fish, 276 — in the lower animals, 275 — structure of the, 273–74 Branchial arches, evolution of the, 303 — cavity, the, 183, 189 — system, the, 110 Branchiotomes, 149 Breasts, the, 113 Bulbilla, 184 C Calamichthys, 234 Calcolynthus, 217 Capillaries, the, 323 Caracoideum, the, 249 Carboniferous strata, 202 Carcharodon, 234 Cardiac cavity, the, 170 Cardiocœl, the, 328 Caryobasis, 38, 54 Caryokinesis, 42 Caryolymph, 38, 54 Caryolyses, 42 Caryon, 37 Caryoplasm, 37 Catallacta, 213 Catarrhinæ, the, 173, 261 Catastrophic theory, the, 24 Caudate cells, 53 Cell, life of the, 41–3 — nature of the, 36–7 — size of the, 38 Cell theory, the, 18, 36 Cenogenesis, 4 Cenogenetic structures, 4 Cenozoic period, the, 203 Central body, the, 38, 42 Central nervous system, the, 273 Centrolecithal ova, 68 Centrosoma, the, 38, 42 Ceratodus, the, 76, 237 Cerebellum, the, 274 Cerebral vesicles, evolution of the, 276 Cerebrum, the, 273 Cestracion Japonicus, 75, 79 Chætognatha, 94 Chick, importance of the, in embryology, 11, 16 Child, mind of the, 8, 355 Chimpanzee, the, 174, 262 Chiromys, 257 Chiroptera, 258 Chirotherium, 239 Chondylarthra, 257 Chorda, the, 17, 95, 107, 183 — evolution of the, 296 Chordæa, the, 97 Chordalemma, the, 296 Chordaria, 97 Chordula, the, 3, 96, 191 Choriata, the, 166 Chorion, the, 119 — development of the, 165–6 — frondosum, 255 — læve, 255 Choroid coat, the, 286 Chorology, 33 Chromacea, 209 Chromatin, 42 Chroococcacea, 210 Chroococcus, the, 210 Church, opposition of, to science in Middle Ages, 10 Chyle, 318 Chyle-vessels, 324 Cicatricula, the, 45, 81 Ciliated cells, 53, 193 Cinghalese gynecomast, 114 Circulation in the lancelet, 184 Circulatory system, evolution of the, 321–25 — — structure of the, 318 Classification, 103 — evolutionary value of, 33 Clitoris, the, 345 Cloaca, the, 249, 317 Cnidaria, 217 Coccyx, the, 295 Cochineal insect, the, 354 Cochlea, the, 289 Cœcilia, 241 Cœcum, the, 310, 317 Cœlenterata, 20, 91, 93, 104 Cœlenteria, 221 Cœloma, the, 21, 64, 91 Cœlomæa, the, 98 Cœlomaria, 21, 91, 104, 221 Cœlomation, 93–4 Cœlom-theory, the, 21, 93 Cœlomula, the, 98 Colon, the, 310, 317 Comparative anatomy, 31 Conception, nature of, 51 Conjunctiva, the, 286 Conocyema, 215 Convoluta, 221 Copelata, the, 197 Copulative organs, evolution of the, 344–45 Corium, the, 108, 268 Cornea, the, 286 Corpora cavernosa, the, 345, 346 Corpora quadrigemina, 274 Corpora striata, 274 Corpus callosum, the, 274 Corpus vitreum, the, 285 Corpuscles of the blood, 319 Craniology, 303 Craniota, the, 182, 229 Cranium, the, 299 Creation, 23–4 Cretaceous strata, 202 Crossopterygii, 234 Crustacea, the, 142, 219 Cryptocœla, 221 Cryptorchism, 114 Crystalline lens, the, 285 — — development of the, 287 Cutaneous glands, 268 Cuttlefish, embryology of the, 9 Cuvier, G., 17, 24 Cyanophycea, 209 Cyclostoma, the, 188, 230–32 — ova of the, 75 Cyemaria, 214 Cynopitheca, 262 Cynthia, 191, 196 Cytoblastus, the, 37 Cytodes, 40 Cytoplasm, 37, 38 Cytosoma, 37 Cytula, the, 54 D Dalton, 15 Darwin, C., 2, 5, 23, 28–9 Darwin, E., 28 Darwinism, 5, 28 Decidua, the, 167 Deciduata, 255 Deduction, nature of, 208 Degeneration theory, the, 219 Dentition of the ape and man, 259 Depula, 62 Descent of Man, 30 Design in organisms, 33 Deutoplasm, 44 Devonian strata, 202 Diaphragm, the, 309 — evolution of the, 328 Dicyema, 215 Dicyemida, 215 Didelphia, 248 Digonopora, 223 Dinosauria, 202 Dipneumones, 238 Dipneusta, 235–38 — ova of the, 75 Dipnoa, 236 Directive bodies, 54 Discoblastic ova, 68 Discoplacenta, 255 Dissatyrus, 174 Dissection, medieval decrees against, 10 Dohrn, Anton, 219 Döllinger, 15 Dorsal furrow, the, 125 — shield, the, 123 — zone, the, 129 Dromatherium, 248 Dualism, 6 Dubois, Eugen, 263 Ductus Botalli, the, 350 Ductus venosus Arantii, 350 Duodenum, the, 309, 317 Duration of embryonic development, 199 — of man’s history, 199 Dysteleology, 32 — proofs of, 349 E Ear, evolution of the, 288–92 — structure of the, 288 — uselessness of the external, 32 Ear-bones, the, 289 Earth, age of the, 200–201 Echidna hystrix, 249 Ectoblast, 20, 64 Ectoderm, the, 20, 64 Edentata, 250 Efficient causes, 6 Egg of the bird, 44–6, 81 — or the chick, priority of the, 211 Elasmobranchs, the, 79 Embryo, human, development of the, 158 Embryology, 2 — evolutionary value of, 34 Embryonic development, duration of, 199 — disk, the, 121–22 — spot, the, 125 Encephalon, the, 273 Endoblast, 20, 64 Endothelia, 321 Enterocœla, 93, 223 Enteropneusta, 226 Entoderm, the, 20, 64 Eocene strata, 203 Eopitheca, 259 Epiblast, 20, 64 Epidermis, the, 108, 268 Epididymis, the, 342 Epigastrula, 80 Epigenesis, 11, 13 Epiglottis, the, 309 Epiphysis, the, 108 Episoma, 129 Episomites, 130, 194 Epispadia, 346 Epithelia, 37 Epitheria, 243, 253 Epovarium, the, 342 Equilibrium, sense of, 291 Esthonychida, 257 Eustachian tube, the, 289 Eutheria, 253 Eve, 12 Evolution theory, the, 11, 208 — inductive nature of, 30 Eye, evolution of the, 285–88 — structure of the, 285 Eyelid, the third, 32 Eyelids, evolution of the, 288 F Fabricius ab Aquapendente, 10 Face, embryonic development of the, 284 Fat glands in the skin, 269 Feathers, evolution of, 270 Fertilisation, 51 — place of, 119 Fin, evolution of the, 239, 304 Final causes, 6 Flagellate cells, 193 Floating bladder, the, 233, 241 — — evolution of the, 314 Fœtal circulation, 170–71 Food-yelk, the, 67, Foot, evolution of the, 241, 304–6 — of the ape and man, 258–59 Fore brain, the, 278 Fore kidneys, the, 336, 337 Fossiliferous strata, list of, 201 Fossils, 180 — scarcity of, 208 Free will, 356 Friedenthal, experiments of, 172 Frog, the, 241–42 — ova of the, 71–2 Frontonia, 224 Function and structure, 7 Furcation of ova, 72 G Gaertner’s duct, 341, 350 Ganglia, commencement of, 268 Ganglionic cell, the, 39 Ganoids, 233, 234 Gastræa, the, 3, 20, 206 — formation of the, 213 Gastræa theory, the, 20, 64, 69 Gastræads, 69, 214 Gastremaria, 214 Gastrocystis, the, 62, 119, 120 Gastrophysema, 215 Gastrotricha, 224 Gastrula, the, 3, 20, 62 Gastrulation, 62 Gegenbaur, Carl, 220 — on evolution, 32 — on the skull, 300–1 Gemmation, 331 General Morphology, 8, 29 Genesis, 23 Genital pore, the, 335 Geological evolution, length of, 200 — periods, 201 Geology, methods of, 180 — rise of, 24 Germ-plasm, theory of, 349 Germinal disk, 46, 81 — layers, the, 14, 16 — — scheme of the, 92 — spot, the, 44 — vesicle, the, 43, 54 Germinative area, the, 121 Giant gorilla, the, 176 Gibbon, the, 173, 262 Gill-clefts and arches, 110 — formation of the, 151–52, 303 Gill-crate, the, 183, 189 Gills, disappearance of the, 244 Glœocapsa, 210 Gnathostoma, 230, 232 Goethe as an evolutionist, 27, 299 Goitre, 110 Gonads, the, 111 — formation of the, 149–50 Gonidia, 334 Gonochorism, beginning of, 322 Gonoducts, 335 Gonotomes, 146, 149 Goodsir, 189 Gorilla, the, 174, 176, 262 Graafian follicles, the, 17, 119, 347 Gregarinæ, 211 Gullet-ganglion, the, 190 Gut, evolution of the, 310–17 Gyrini, 242 Gynecomastism, 114 H Hag-fish, the, 188 Hair, evolution of the, 270 — on the human embryo and infant, 271 Hair, restriction of, by sexual selection, 271 Haliphysema, 215 Halisauria, 202 Haller, Albrecht, 12 Halosphæra viridis, 213 Hand, evolution of the, 250, 304–6 — of the ape and man, 258 Hapalidæ, 261 Harderian gland, the, 288 Hare-lip, 284 Harrison, Granville, 161 Hartmann, 262 Harvey, 10 Hatschek, 192 Hatteria, 243, 246 Head-cavity, the, 138 Head-plates, the, 149 Heart, development of the, 7, 10, 111, 151, 170, 322, 324–27 — of the ascidia, 190 — position of the, 327 Helmholtz, 207 Helminthes, 223 Hepatic gut, the, 109, 316 Heredity, nature of, 3, 5, 27, 56–7, 349 Hermaphrodism, 9, 23, 114, 218, 322, 346 Hertwig, 21 Hesperopitheca, 259 His, W., 19 Histogeny, 18, 19 History of Creation, 6, 30 Holoblastic ova, 67, 71, 77 Homœosaurus, 244, 246 Homology of the germinal layers, 20 Hoof, evolution of the, 270 Hunterian ligament, the, 344 Huxleian law, the, 171, 257, 262 Huxley, T. H., 7, 20, 29 Hydra, the, 69, 217 Hydrostatic apparatus in the fish, 315 Hylobates, 173, 262 Hylodes Martinicensis, 241 Hyoid bone, the, 299 Hypermastism, 113 Hyperthelism, 113 Hypoblast, 20, 64 Hypobranchial groove, the, 110, 184, 226, 316 Hypodermis, the, 268 Hypopsodina, 257 Hyposoma, the, 129 Hyposomites, 130, 194 Hypospadia, 346 I Ichthydina, 224 Ichthyophis glutinosa, 80 Ictopsida, 257 Ileum, the, 310 Immortality, Aristotle on, 10 Immortality of the soul, 58 Impregnation-rise, the, 55 Indecidua, 255 Indo-Germanic languages, 203 Induction and deduction, 31, 208 Inheritance of acquired characters, 349 Insects, intelligence of, 353 Interamniotic cavity, the, 165 Intestines, the, 309, 316–17 Invagination, 62 Iris, the, 286 J Jacchus, 261 Java, ape-man of, 263, 264 Jaws, evolution of the, 301 Jurassic strata, 202 K Kant, dualism of, 25 Kelvin, Lord, on the origin of life, 207 Kidneys, the, 111 — formation of the, 150–51, 336–42 Klaatsch, 262 Kölliker, 21 Kowalevsky, 191 L Labia, the, 346 Labyrinth, the, 290 Lachrymal glands, 269 Lamarck, J., 23, 25–7 — theories of, 26, 349 Lamprey, the, 230 — ova of the, 75 Lancelet, the, 60, 181–95 — description of the, 105 Languages, evolution of, 203 Lanugo of the embryo, 271 Larynx, the, 309 — evolution of the, 314 Latebra, the, 45 Lateral plates, the, 129 Laurentian strata, 201 Lecithoma, the, 117 Leg, evolution of the, 304 — structure of the, 306 Lemuravida, 257 Lemurogona, 257 Lemurs, the, 257 Lepidosiren, 257 Leucocytes, 319 Life, age of, 200 Limbs, evolution of the, 152, 239, 304 Limiting furrow, the, 133 Linin, 42 Liver, the, 309, 317 Long-nosed ape, the, 164 Love, importance of in nature, 332 Lungs, the, 110 — evolution of the, 241, 314–15 Lyell, Sir C., 24 Lymphatic vessels, the, 318 Lymph-cells, the, 319 M Macrogonidion, 331 Macrospores, 331 Magosphæra planula, 213 Male womb, the, 344, 350 Mallochorion, the, 166 Mallotheria, 257 Malpighian capsules, 339, 341 Mammal, characters of the, 112 — gastrulation of the, 84 Mammals, unity of the, 247–48 Mammary glands, the, 113, 269 Man and the ape, relation of, 262, 351 — origin of, 29 Man’s Place in Nature, 7, 29, 351 Mantle, the, 189 Mantle-folds, the, 185 Marsupials, the, 250–52 — ova of the, 85 Materialism, 356 Mathematical method, the, 30 Mechanical causes, 6 — embryology, 8, 19, 22 Meckel’s cartilage, 304 Medulla capitis, the, 273 — oblongata, the, 274 — spinalis, the, 273 Medullary groove, the, 125 — tube, the, 107, 128 — — formation of the, 131, 133, 227, 267, 276 Mehnert, E., on the biogenetic law, 5 Meroblastic ova, 67, 71, 78 Merocytes, 68, 321 Mesentery, the, 98, 109, 310, 316 Mesocardium, the, 327 Mesoderm, the, 20, 64, 90, 93 Mesogastria, 215 Mesonephridia, the, 338 Mesonephros, the, 336 Mesorchium, the, 344 Mesovarium, the, 344 Mesozoic period, the, 202 Metogaster, the, 64 Metagastrula, the, 67 Metamerism, 142 Metanephridia, the, 341 Metanephros, the, 336 Metaplasm, 39 Metastoma, 64, 222 Metatheria, 248 Metazoa, 20, 62 Metovum, the, 81 Microgonidian, 331 Microspores, 331 Middle ear, the, 291 Migration, effect of, 33 Milk, secretion of the, 269 Mind, evolution of, 353–54 — in the lower animals, 353 Miocene strata, 203 Mitosis, 40, 41 Monera, 40, 206, 209 Monism, 6, 356 Monodelphia, 248 Monogonopora, 223 Monopneumones, 238 Monotremes, 118, 249 — ova of the, 84 Monoxenia Darwinii, 60 Morea, the, 212 Morphology, 2, 27 Morula, the, 62, 212 Motor-germinative layer, the, 19 Mouth, development of the, 124, 139 — structure of the, 308 Mucous layer, the, 16 Müllerian duct, the, 341 Muscle-layer, the, 16 Muscles, evolution of the, 307 — of the ear, rudimentary, 292 Myotomes, 108, 146 Myxinoides, the, 188, 230 N Nails, evolution of the, 270 Nasal pits, 284 Natural philosophy, 25 — selection, 26, 28, 349 Navel, the, 117, 134 Necrolemurs, 257 Nectocystis, the, 314 Nemertina, 224–26 Nephroduct, evolution of the, 338–39 Nephrotomes, 149, 338 Nerve-cell, the, 39 Nerves, animals without, 267 Nervous system, evolution of the, 7, 267 Neurenteric canal, the, 127 Nictitating membrane, the, 32, 286, 288 Nose, the, in man and the ape, 164 — development of the, 282–85 — structure of the, 283 Notochorda, the, 107 Nuclein, 37 Nucleolinus, 44 Nucleolus, the, 38, 44, 54 Nucleus of the cell, 37 O Œsophagus, the, 309, 316 Oken, 5, 27, 300 Oken’s bodies, 339 Oligocene strata, 203 Olynthus, 217 On the generation of animals, 9 Ontogeny, 2, 23 — defective evidence of, 208 Opaque area, the, 122 Opossum, the, 252 — ova of the, 85 Optic nerve, the, 287 Optic thalami, 274 — vesicles, 286 Orang, the, 174, 262 Ornithodelphia, 248 Ornithorhyncus, 85, 249 Ornithostoma, 249 Ossicles of the ear, 289 Otoliths, 289 Ova, number of, 347 — of the lancelet, 192 Ovaries, evolution of the, 333–34 Oviduct, origin of the, 335, 342 Ovolemma, the, 44 Ovulists, 12 Ovum, discovery of the, 16 — nature of the, 40 — size of the, 44 P Pachylemurs, the, 257 Pacinian corpuscles, 282 Paleontology, 2 — evolutionary evidence of, 31 — incompleteness of, 208 — rise of, 24 Paleozoic age, the, 202 Palingenesis, 4 Palingenetic structures, 4 Palæhatteria, 244, 246 Panniculus carnosus, the, 350 Paradidymis, the, 342 Parietal zone, the, 129 Parthenogenesis, 9, 13 Pastrana, Miss Julia, 164 Pedimana, 252 Pellucid area, the, 122 Pelvic cavity, the, 138 Pemmatodiscus gastrulaceus, 215 Penis-bone, the, 346 Penis, varieties of the, 345 Peramelida, 254 Periblastic ova, 68 Peribranchial cavity, the, 185, 190 Pericardial cavity, the, 328 Perichorda, the, 108, 183 — formation of the, 136 Perigastrula, 89 Permian strata, 202 Petromyzontes, the, 188, 230 Phagocytes, 49, 320 Pharyngeal ganglion, the, 275 Pharynx, the, 309 Philology, comparison with, 203 Philosophie Zoologique, 25 Philosophy and evolution, 6 Phycochromacea, 209 Phylogeny, 2, 23 Physemaria, 214 Physiology, backwardness of, 7 Phytomonera, 209 Pineal eye, the, 108 Pinna, the, 291 Pithecanthropus, 263, 264 Pithecometra-principle, the, 171 Placenta, the, 166, 253–54 Placentals, the, 166 — characters of the, 253 — gastrulation of the, 86 Planocytes, 49, 320 Plant-louse, parthenogenesis of the, 13 Planula, the, 89 Plasma-products, 38, 39 Plasson, 40, 59 Plastids, 36, 40, 209 Plastidules, 59 Platodaria, 221 Platodes, the, 221 Platyrrhinæ, 261 Pleuracanthida, 234 Pleural ducts, 328 Pliocene strata, 203 Polar cells, 54 Polyspermism, 58 Preformation theory, the, 11 Primary period, the, 202 Primates, the, 157, 257–60 Primatoid, 263 Primitive groove, the, 69, 82, 124, 125 — gut, the, 20, 63, 214 — kidneys, the, 111, 337 — mouth, the, 20, 63 — segments, 143 — streak, the, 100, 122 — vertebræ, 144, 195, 206, 229 Primordial period, the, 201 Prochordata, 192 Prochordonia, the, 192, 218 Prochoriata, 253 Prochorion, the, 44, 119 Proctodæum, the, 345 Procytella primordialis, 210 Prodidelphia, 256 Progaster, the, 20, 63 Progonidia, 333 Promammalia, 247 Pronephridia, the, 151 Pronucleus femininus, 54 — masculinus, 54 Properistoma, 69 Prorenal canals of the lancelet, 186 — duct, the, 132, 139, 186 — — evolution of the, 338 Proselachii, 234 Prosimiæ, the, 257 Prospermaria, 333 Prospondylus, 105, 229 Prostoma, 20, 63, 222 Protamniotes, 243–44 Protamœba, 210 Proterosaurus, the, 202, 244 Protists, 36, 38 Protonephros, 111, 336 Protophyta, 210 Protoplasm, 37, 209 Protopterus, 238 Prototheria, 248 Protovertebræ, 142, 144 Protozoa, 20, 210 Provertebral cavity, the, 148 — plates, the, 136, 144 Pseudocœla, 93, 221 Pseudopodia, 48 Pseudova, 13 Psychic life, evolution of the, 8 Psychology, 8 Pterosauria, 202 Pylorus, the, 309 Q Quadratum, the, 247 Quadrumana, 258 Quaternary period, 203 R Rabbit, ova of the, 86–7 Radiates, the, 103 Rathke’s canals, 341 Rectum, the, 317 Regner de Graaf, 119 Renal system, evolution of the, 335–42 Reproduction, nature of, 330–31 Reptiles, 245–47 Respiratory organs, evolution of the, 314–15 — pore, the, 183, 189 Retina, the, 286 Rhabdocœla, 222 Rhodocytes, 319 Rhopalura, 215 Rhyncocephala, 243 Ribs, the, 295 — number of the, 353 Rudimentary ear-muscles, 292 — organs, 32 — — list of, 349–50 — toes, 306 S Sacculus, the, 289 Sagitta, 65, 66, 191 — cœlomation of, 93 Salamander, the, 241 — ova of the, 74 Sandal-shape of embryo, 128–29 Satyrus, 174, 262 Sauromammalia, 246 Sauropsida, 245 Scatulation theory, the, 12 Schizomycetes, 210 Schleiden, M., 18, 36 Schwann, T., 18, 36 Sclerotic coat, the, 286 Sclerotomes, 108, 143, 148 Scrotum, the, 344 Scyllium, nose of the, 283 Sea-squirt, the, 181, 188–90 Secondary period, the, 202 Segmentation, 60, 141–42 Segmentation-cells, 54 Segmentation-sphere, the, 17 Selachii, 223 — skull of the, 301 Selection, theory of, 28 Selenka, 166, 168 Semnopitheci, 262 Sense-organs, evolution of the, 151, 280 — number of the, 281 — origin of the, 281 Sensory nerves, 279 Serocœlom, the, 165 Serous layer, the, 16 Sex-organs, early vertebrate form of the, 111 — evolution of the, 333 Sexual reproduction, simplest forms of, 331 — selection, 30, 271–72 Shark, the, 233 — nose of the, 283 — ova of the, 75 — placenta of the, 9 — skull of the, 301 Shoulder-blade, the, 306 Sickle-groove, the, 82, 121 Sieve-membrane, the, 167 Silurian strata, 202 Simiæ, the, 257–60 Siphonophoræ, embryology of the, 21 Skeleton, structure of the, 294 Skeleton-plate, the, 148 Skin, the, 151 — evolution of, 266–69 — function of the, 269 Skin-layer, the, 16 Skull, evolution of the, 149, 299–303 — structure of the, 299 — vertebral theory of the, 300 Smell, the sense of, 282 Soul, evolution of the, 353–56 — nature of the, 58, 356 — phylogeny of the, 8 — seat of the, 278 Sound, sensations of, 289–90 Sozobranchia, 242 Space, sense of, 291 Species, nature of the, 23, 34 Speech, evolution of, 264 Spermaducts, 335, 342 Spermaries, evolution of the, 333–34 Spermatozoon, the, 52–3 — discovery of the, 12, 53 Spinal cord, development of the, 8 — structure of the, 273 Spirema, the, 42 Spiritualism, 356 Spleen, the, 318 Spondyli, 142 Sponges, classification of the, 34 — ova of the, 49 Spontaneous generation, 26, 206 Stegocephala, 239 Stem-cell, the, 54 Stem-zone, the, 129 Stomach, evolution of the, 311–14, 316 — structure of the human, 309 Strata, thickness of, 200–201 Struggle for life, the, 28 Subcutis, the, 268 Sweat glands, 269 T Tactile corpuscles, 268, 282 Tadpole, the, 242 Tail, evolution of the, 242–43 — rudimentary, in man, 159, 295, 350 Tailed men, 160–61 Taste, the sense of, 282 Teeth, evolution of the, 314 — of the ape and man, 259 Teleostei, 234 Telolecithal ova, 67, 68 Temperature, sense of, 282 Terrestrial life, beginning of, 235 Tertiary period, the, 203 Theoria generationis, the, 13 Theories, value of, 181 Theromorpha, 246 Third eyelid, the, 286, 288 Thyroid gland, the, 110, 184, 315 Time-variations in ontogeny, 5 Tissues, primary and secondary, 37 Toad, the, 241 Tocosauria, 246 Toes, number of the, 240 Tori genitales, the, 346 Touch, the sense of, 282 Tracheata, 142, 219 Tread, the, 45, 81 Tree-frog, the, 241 Triassic strata, 202 Triton tæniatus, 74 Troglodytes, 174 Tunicates, the, 189 Turbellaria, 222 Turbinated bones, the, 283 Tympanic cavity, the, 288 U Umbilical, cord, the, 117 — vesicle, the, 138 Unicellular ancestor of all animals, 47 — animals, 38, 47 Urachus, the, 317, 341 Urinary system, evolution of the, 335–42 Urogenital ducts, 335 Uterus masculinus, the, 344, 350 Utriculus, the, 289 V Vasa deferentia, 335 Vascular layer, the, 16, 168 — system, evolution of the, 321–25 — — structure of the, 318 Vegetative layer, the, 16 Veins, evolution of the, 323–24 Ventral pedicle, the, 166 Ventricles of the heart, 325 Vermalia, 220, 223 Vermiform appendage, the, 32, 310, 317 Vertebræ, 142, 294 Vertebræa, 105 Vertebral arch, the, 148, 295 — column, the, 144 — — evolution of the, 296 — — structure of the, 294 Vertebrates, character of the, 104–10 — descent of the, 219–20 Vertebration, 142 Vesico-umbilical ligament, the, 341 Vesicula prostatica, the, 344, 350 Villi of the chorion, 165 Virchow, R., 35 — on the ape-man, 303 — on the evolution of man, 264 Virgin-birth, 9, 13 Vitalism, 6 Vitelline duct, the, 138 Volvocina, 213 W Wallace, A. R., 29 Water, organic importance of, 200 Water vessels, 336 Weismann’s theories, 349 Wolff, C. F., 13 Wolffian bodies, 339 Wolffian duct, the, 341 Womb, evolution of the, 342–43 Y Yelk, the, 43, 45, 67 Yelk-sac, the, 117, 134 Z Zona pellucida, the, 44 Zonoplacenta, 255 Zoomonera, 209 Zoophytes, 20, 64, 104