Front matter (continued 12)

Acilius larva, eye of, 78, 83 Acromegaly, 425 Actinotrocha, 438 Addison's disease, 423 Adelopthalmus, 249 Adrenalin, 423, 491 Adrenals, 423, 491 Agnathostomatous fishes, 29, 343 Alimentary canal, 433 Alim"ntary c"nal, Ammocœtes, 168, 405, 445 Alim"ntary c"nal, invertebrate, compared to tube of central nervous system of vertebrate, 43, 433 Alim"ntary c"nal, innervation of, 447 Alim"ntary c"nal, origin of, 444 Alim"ntary c"nal, position of vertebrate and invertebrate, 10 Alim"ntary c"nal, possibility of formation of new, 58 Alim"ntary c"nal, relationship between notochord and, 434 Ammocœtes, 32, 245 Ammo"œtes, an ancestral type, 35, 309 Ammo"œtes, alimentary canal, 168, 405, 445 Ammo"œtes, auditory organ, 378, 379 Ammo"œtes, brain, 39, 40, 41, 45, 46, 48, 54, 61 Ammo"œtes, branchial appendages, 161, 162, 163, 164 Ammo"œtes, bra"chial basket-work, 126, 128, 296, 331, 335 Ammo"œtes, bra"chial chamber, 161, 168, 162, 163 Ammo"œtes, bra"chial circulation in Limulus and, 174 Ammo"œtes, bra"chial diaphragms, 161, 167 Ammo"œtes, bra"chial lamellæ, 175 Ammo"œtes, bra"chial muscles, 171 Ammo"œtes, bra"chial nerves, 164 Ammo"œtes, bra"chial segments, 178, 312 Ammo"œtes, cartilage, hard, 133, 133, 293, 294, 377 Ammo"œtes, cart"lage, muco, 130, 131, 291, 293, 294, 296, 330, 331, 333, 334, 335, 338 Ammo"œtes, cart"lage, soft, 129, 130, 293, 294, 296, 335 Ammo"œtes, degeneracy, evidence of, 59, 94, 343 Ammo"œtes, development, 228, 458 Ammo"œtes, digestion, 58, 442 Ammo"œtes, epithelial cells of gills, 214 Ammo"œtes, epithelial cells of skin, 347 Ammo"œtes, epit"elial pits, 173, 200 Ammo"œtes, eye, 93 Ammo"œtes, e"e, muscles, 267 Ammo"œtes, e"e, median or pineal, 63, 75, 76, 77, 78, 80, 85, 86 Ammo"œtes, e"e, me"ian or pi"eal left, 78, 79 Ammo"œtes, fat-column, 181, 182 Ammo"œtes, f"t in degenerated muco-cartilage, 333, 334 Ammo"œtes, ganglia in embryo, 229, 283 Ammo"œtes, gland-tissue round the brain, 209, 210, 379 Ammo"œtes, head-region, 128, 162, 163, 193, 293, 294, 296, 298, 335 Ammo"œtes, head-shield, 329, 331, 338 Ammo"œtes, liver, 442, 452 Ammo"œtes, lymphatic glandular tissue, 426 Ammo"œtes, Müllerian fibres, 489 Ammo"œtes, muscles, eye, 173, 267 Ammo"œtes, mu"cles, lip, lower, 297 Ammo"œtes, mu"cles, li",| upper, 305 Ammo"œtes, mu"cles,| respiratory, 171 Ammo"œtes, mu"cles,| somatic, 332, 336, 409 Ammo"œtes, mu"cles,| tubular, 173, 298, 309 Ammo"œtes, nerves, cranial, 141 Ammo"œtes, ne"ves, facial, 186, 311 Ammo"œtes, ne"ves, glossopharyngeal, 186 Ammo"œtes, ne"ves, optic, 105 Ammo"œtes, ne"ves, trigeminal, 282, 288, 288 Ammo"œtes, ne"ves, vagus, 153, 173, 186 Ammo"œtes, nerve-fibres, medullation of, 20 Ammo"œtes, notochord, 182, 435 Ammo"œtes, olfactory tube, 219, 225, 227, 317 Ammo"œtes, oral chamber, 317, 243, 287, 458 Ammo"œtes, parasitism, 60, 286 Ammo"œtes, pituitary, 321 Ammo"œtes, prosomatic region, 243 Ammo"œtes, pronephric duct, 402, 405 Ammo"œtes, relationship to Ostracodermata, 326, 338, 344, 414, 416 Ammo"œtes, retina, 93, 111 Ammo"œtes, skin, 58, 346, 348, 442 Ammo"œtes, skeleton, 125, 126, 132, 291, 296, 335 Ammo"œtes, segments, comparison with segments of Eurypterus, 323 Ammo"œtes, segm"nts, facial, 201 Ammo"œtes, segm"nts, hyoid, 186, 201 Ammo"œtes, segm"nts, prosomatic, 286 Ammo"œtes, septa between myomeres, 416 Ammo"œtes, tentacles of upper lip, 303 Ammo"œtes, test, biological, to show relationship with Limulus, 493 Ammo"œtes, thyroid, 192, 194, 196, 205, 213, 430 Ammo"œtes, transformation, 18, 59, 125, 168, 193, 199, 200, 220, 227, 228, 287, 291, 304, 307, 309, 331, 336, 347, 349, 389, 445 Ammo"œtes, velum, 228, 289, 298, 302 Amœbocytes, 473 Amphibia, 23, 345 Amphioxus, 33, 407 Amphi"xus, atrial cavity, 409 Amphi"xus, branchial nephric glands, 426 Amphi"xus, endostyle, 198, 212 Amphi"xus, excretory organs, 389, 395, 477 Amphi"xus, neuropore, 220, 457 Amphi"xus, notochord, 435, 436, 443 Amphi"xus, pleural folds, 495 Amphi"xus, septa between myomeres, 416 Amphi"xus, somatic muscles, 409 Amphi"xus, yolk, 485 Androctonus, 53, 54, 372, 423 Annelids, lateral sense-organs, 357, 367 Ann"lids, nephric organs, 390 Ann"lids, rigin of Arthropods from, 395 Ann"lids, parapodal ganglia, 283 Ann"lids, phagocytic glands, 421 Anthozoa, 474 Antiarcha, 29, 326, 343 Antibody, 492 Antitoxin, 492 Anus, 43, 457 Aponeuroses, 327, 342, 414 Apparatus, auditory, 355 Appa"rtus, dioptric, 83 Appa"rtus, respiratory, 148 Appa"rtus, suctorial, of Petromyzon, 287 Appendages, branchial, of Ammocœtes, 161, 162, 163, 164 Appe"dages, bra"chial, of Limulus, 164 Appe"dages, bra"chial, of internal, 149 Appe"dages, derivation of suctorial apparatus of Petromyzon from, 290 Appe"dages, disappearance of, in transformation of Arthropod into Vertebrate, 386, 413 Appe"dages, evidence of, in prosomatic region of ancient fishes, 342 Appe"dages, muscles, in Limulus and Scorpion, 247 Appe"dages, prosomatic, of Gigantostraca, 234 Appe"dages, Trilobites, 351 Apus, 28, 137, 436, 437 Arachnids, eyes, 75, 87 Arac"nids, diverticula of stomach, 109 Arac"nids, lyriform organs, 364, 368 Arac"nids, segmental excretory organs, 423 Archæocytes, 473 Artemia, v. Branchipus Arthropleura, 249 Arthropoda, arrangement of organs, 10 Arthr"poda, evolution, 11 Arthr"poda, excretory organs, 396, 418 Arthr"poda, eyes, 75, 89 Arthr"poda, giant-fibres, 489 Arthr"poda, musculature, 411 Arthr"poda, olfactory organs, 220 Arthr"poda, resemblance to ancient fishes, 29 Astacus, brain, 54 Ast"cus, digestive ferment in cells lining the carapace, 442 Ast"cus, optic chiasma, 101 Ast"cus, optic stalk, 91 Ast"cus, etina, 98 Asterolepis, 326, 342 Atrium, 410 Auchenaspis (Thyestes), 30, 31, 75, 275, 326, 327, 328, 338 Auditory apparatus, 355 Auerbach, plexus of, 447 Aurelia, 475 Autonomic nerves, 3 Balanoglossus, 12, 12, 433, 438, 494 Bdellostoma, 394, 405 Belinurus, 24, 249, 351 Bird, rhomboidal sinus, 46 Bladder, 449 Bla"der, swim, 148 Blastula, 459, 471, 473 Blood, 463, 472, 474 Bl"od, circulation, in Ammocœtes and Limulus, 174 Bl"od, secretion of ductless glands into, 418 Bothriolepis, 29, 32, 239, 326, 351, 450 Bone, 344, 474, 481 Brain, Ammocœtes and Arthropod, 54, 61 Br"in, and brain-case of Ammocœtes, 40, 41, 46, 209 Br"in, caudal, of Thelyphonus, 450 Br"in, epithelial lining of, 38 Br"in, roof, 39 Br"in, Sphæroma serratum, 62, 90 Br"in, Thelyphonus, 56 Br"in, ventricles, 4 Br"in, vesicles, 48 Branchial basket-work of Ammocœtes, 126, 128, 296, 331, 335 Branchipus, 28 Bran"hipus, brain, 51, 54 Bran"hipus, eyes, lateral, 88 Bran"hipus, e"es, lat"ral, retina of, 91, 97 Bran"hipus, e"es, median, 75 Bran"hipus, excretory organs, 396 Bran"hipus, (Artemia) diverticula of gut and retinal ganglion, 110, 111, 113 Bran"hipus, nerves of appendages, 157 Bran"hipus, segmentation, 159 Bran"hipus, resemblance to Trilobite, 436 Bunodes, 24, 30, 249, 341, 351, 414 Bundle of Meynert, 48, 77 Bundles, posterior longitudinal, 489 Buthus, muscles, 270 Calcification in aponeuroses of Cephalaspis, 414 Calcifi"ation cartilage, 140,330 Calcifi"ation successive layers of the skin, 348 Camerostome, 221, 222, 223, 224, 241, 271 Canal, alimentary, formation of vertebrate, 58, 433, 446 Ca"al, alime"tary, innervation, 447 Ca"al, alime"tary, relationships between notochord and, 434 Ca"al, alime"tary, origin, 444 Ca"al, Haversian, 329 Ca"al, central, of spinal cord, 405, 439, 455 Ca"al, spinal, 182 Capsule, auditory, 377, 379 Cartilage Ammocœtes, muco, 127, 130, 131, 200, 291, 303, 330, 333, 334, 344 Cart"ilge Ammo"œtes, hard, 133, 133, 377 Cart"ilge Ammo"œtes, soft, 126, 129, 130 Cart"ilge Ammo"œtes, spinal cartilages, 414 Cart"ilge Hypoctonus, 133, 142 Cart"ilge Limulus, hard, 142 Cart"ilge Lim"lus, muco, 139 Cart"ilge Lim"lus, soft, 20, 130, 137 Cart"ilge origin, 474, 481 Cart"ilge staining reactions, 131, 133, 139, 330, 336 Cavity, atrial, 409, 413 Cai"ty, cœlomic, 167, 251, 266, 320, 389, 391, 408, 422, 430, 472 Cells, free-living, 463 Centre, vaso-motor, 468 Cephalaspis, diverticula of gut, 109 Ceph"laspis, eyes, lateral, 75, 275 Ceph"laspis, e"es, median, 75 Ceph"laspis, head-shield, 327, 328, 330, 338 Ceph"laspis, muscles on head-shield, 269 Ceph"laspis, resemblance to Ammocœtes, 145, 291, 326, 329, 338, 348, 414 Ceph"laspis, resem"lance to Arthropod, 29 Ceph"laspis, segmentation, 339 Ceratodus, 148 Cephalization, 51 Cephalodiscus, 438 Cephalopod, 23 Cerebellum, 47, 50 Chætopoda, 395 Chamber, oral, of Ammocœtes, 243, 287, 458 Cheliceræ, 235 Chiasma, optic, 101 Chilaria, 235, 238, 291, 301, 458 Chitin, 85, 119, 139, 205, 206, 302, 329, 346, 359, 440, 443 Cilia, 206 Circulation, branchial, 174 Cirri, 357 Clarke's column, 467 Clepsine, nephridial glands, 423 Cochlea, 378 Cœlenterata, 465, 472 Cœlolepidæ, 344 Cœlom, 167, 251, 400, 472, 481 Cœlomata, 472 Cœlomocœla, 472, 475 Cœlomostomes, 477, 481 Colleneytes, 474 Commissure, anterior, 49 Comm"ssure, œsophageal, 14 Comm"ssure, posterior, 48, 280 Comparison of brains of Ammocœtes and Arthropod, 61 Comp"rison of br"ins of invertebrate from Branchipus to Ammocœtes, 54 Comp"rison of br"ins of vertebrate, 40 Comp"rison of branchial circulation in Ammocœtes and Limulus, 174 Comp"rison of bran"hial lamellæ of Scorpion and Ammocœtes, 175 Comp"rison of bran"hial segments of Ammocœtes and Petromyzon, 169 Comp"rison of Cephalaspidian and Palæostracan fish, 31 Comp"rison of Cœlom of Peripatus and Vertebrate, 400 Comp"rison of dermal covering of Pteraspis with chitin of Limulus or dentine of fish scales, 346 Comp"rison of entosternite or plastron of Limulus with trabeculæ of Ammocœtes, 145 Comp"rison of excretory organs of vertebrates and invertebrates, 389 Comp"rison of gut of Arthropod and tube of central nervous system of Vertebrate, 43, 244, 433, 440, 455, 457 Comp"rison of head-shield of Cephalaspis and Ammocœtes, 291, 329, 338 Comp"rison of hypophysial tube with olfactory tube of Arthropod ancestor, 229 Comp"rison of hypop"ysial t"be with position of palæostoma, 317 Comp"rison of mesosomatic region of Ammocœtes and Eurypterus, 192 Comp"rison of muscles, branchial, of Ammocœtes and appendage muscles of Scorpion, 171, 447 Comp"rison of mu"cles, eye, of Vertebrate with dorso-ventral muscles of Scorpion, 267, 272, 459 Comp"rison of mu"cles, of oral chamber of Ammocœtes and prosomatic musculature of Limulus, 247, 447 Comp"rison of mu"cles, longitudinal body-muscles of Vertebrate and dorsal longitudinal muscles of Arthropod, 411, 447 Comp"rison of nerves, appendage of Limulus and Branchipus to lateral root system of Vertebrate, 157 Comp"rison of ne"ves, cranial and spinal segmental, 152 Comp"rison of nervous systems of Vertebrate and Arthropod, 36 Comp"rison of pineal gland of vertebrates and median eyes of Arthropod, 63, 456 Comp"rison of pituitary body and coxal glands, 246, 319, 321 Comp"rison of prosoma and mesosoma of Limulus and Ammocœtes, 140, 141 Comp"rison of prosomatic region of Ammocœtes and Eurypterus, 244, 333 Comp"rison of retina in Ammocœtes and Musca, 97 Comp"rison of re"ina compound in Arthropod and Vertebrate, 87 Comp"rison of skeleton of Limulus and Ammocœtes, 126, 136 Comp"rison of sense-organs of Arthropod appendages with auditory organs of Vertebrate, 375 Comp"rison of thyroid with endostyle, 198 Comp"rison of thy"oid w"th uterus of Scorpion, 205 Corneagen, 69 Corpora quadrigemina, 47 Corpuscles, Pacinian, Herbst, Grandry, etc., 470 Coxal glands, 242, 246, 319, 321, 389, 398, 403, 429 Cranium, 121, 145, 339 Crayfish, 442, 489 Crest, neural, 281 Cromatophores of frog, 470 Crura cerebri, 14 Crustacea, first appearance, 27 Crust"cea, eyes, 76, 87 Crust"cea, retina, 100 Crust"cea, segmental glands, 422 Ctenophora, 474 Cyathaspis, 29, 326, 340, 343 Cyclostomata, 165, 229, 343, 353, 424 Cysts, 50 Daphnia, 112 Degeneration, 17, 19, 59, 74, 78, 94, 107, 212, 309, 333, 336, 343 Deiters' nucleus, 489 Dendrites, 72 Development, parallel, 497 Devel"pment, of two types of eye, 73 Devel"pment, vertebrate retina, 101 Diaphragms, 161, 167 Didymaspis, 327, 338 Digestion, 441 Dinosaurs, 17 Dipnoans, 23, 45, 148 Diptera, 89, 369 Diverticula, optic, 102 Dogfish, skull, 121, 123 Drepanaspis, 344, 345, 450 Drepanopterus Bembycoides, 238 Ectognath, 238, 242, 271, 304, 342, 381 Eel, 488 Elasmobranchs, 23, 343, 423 Elastin, 435 Embryo, head of dogfish, 121, 123 Em"ryo, skull of pig, 121 Embryology, principles of, 455 Encepalomeres, 262 Endognath, 238, 271, 304, 381 Endostoma, 241, 306 Endostyle, 198, 212 Entapophysis of Limulus, 139 Enterocœla, 472 Enteropneusta, 438, 494 Entochondrites, 377 Entosclerite, 222, 271 Entosternite, 143 Epiblast, 444, 445, 459 Epithelium cells of Ammocœtes, 347 Epith"lium of central nervous system of vertebrates, 38, 457 Epith"lium of cœlomic spaces in annelids, 421 Epith"lium of optic diverticula, 103 Epith"lium of peritoneal, pleural, and pericardial cavities, 477 Epith"lium of velum of Ammocœtes, 301, 302 Equilibration, 358 Eukeraspis, 326 Eurypterus, 26, 150, 191, 237 Eury"terus, appendages, 150, 236, 237 Eury"terus, classification, 249 Eury"terus, comparison with Ammocœtes, 170, 323 Eury"terus, diagram of sagittal median section, 240, 245 Eury"terus, endostoma, 241, 306 Eury"terus, eyes, 275 Eury"terus, mesosomatic segments, 192 Eury"terus, muscles of carapace, 269 Eury"terus, operculum, 150, 190, 212 Evidence of alimentary canal, innervation, 446 Evide"ce of auditory apparatus and lateral line organs, 355 Evide"ce of cœlomic cavities in Limulus, 251 Evide"ce of degeneracy in Ammocœtes, 59, 94, 343 Evide"ce of embryology, cartilage, 20, 129 Evide"ce of embry"logy, eye-muscles, 263 Evide"ce of embry"logy, excretory organs, 390 Evide"ce of embry"logy, heart, 179, 451 Evide"ce of embry"logy, nervous system, central, cerebral vesicles, 48, 458 Evide"ce of embry"logy, ner"ous sy"tem, ce"tral, epithelial tube, 37, 42, 102, 244, 433, 455 Evide"ce of embry"logy, ner"ous sy"tem, ce"tral, neurenteric canal, 37 Evide"ce of embry"logy, ner"ous sy"tem, ce"tral, neuropore, 220, 457 Evide"ce of embry"logy, ner"ous sy"tem, ce"tral, optic diverticula, 102 Evide"ce of embry"logy, ner"ous sy"tem, ce"tral, spinal cord, 46 Evide"ce of embry"logy, oral chamber, 228, 242, 243, 290 Evide"ce of embry"logy, olfactory organ, 220, 227 Evide"ce of embry"logy, palæostoma or old mouth, 317 Evide"ce of embry"logy, pineal or median eyes, 15, 63, 74, 456 Evide"ce of embry"logy, pituitary body and coxal glands, 246, 319 Evide"ce of embry"logy, thyroid, 192, 194 Evide"ce of embry"logy, segmentation, double, of head, 157, 234, 258 Evide"ce of embry"logy, skeleton, cranial, 120, 153 Evide"ce of nervous system, central, 8 Evide"ce of notochord, origin from segmented region, 443 Evide"ce of olfactory apparatus, 218 Evide"ce of organs of vision, 68 Evide"ce of palæontology, 20, 497 Evide"ce of pineal or median eyes, 74 Evide"ce of prosomatic musculature, 247 Evide"ce of respiratory apparatus, 148 Evide"ce of segmentation in head-shield, 339 Evide"ce of skeleton, 119 Evolution, 8, 15, 20, 149, 482, 497 Evol"tion, of brain in brain-case, 210 Evol"tion, of cranium of Vertebrate, 342 Evol"tion, of excretory organs, 389 Evol"tion, of eye of Vertebrate, 114 Evol"tion, of nervous system, central, 34 Evol"tion, of tissues, 19 Evol"tion, of Vertebrate from Balanoglossus and Amphioxus, 33 Eyes, 68 Ey"s, lateral, 87, 105, 108 Ey"s, median or pineal, 74, 77, 78, 79 Fat-cells in muco-cartilage, 332 Fat-column of Ammocœtes, 181, 182 Fibres, Mauthnerian, 488 Fib"rs, Müllerian, of Ammocœtes central nervous system, 489 Fib"rs, Müll"rian, of retina, 96, 107 Fishes, classification, 218 Fis"es, ancient, classification, 326, 343 Fis"es, ani"ent, cloacal region, 450 Fis"es, ani"ent, dominance, 23 Fis"es, ani"ent, eyes, 75 Fis"es, ani"ent, head-shields. See Head-shields Fis"es, ani"ent, pleural folds, 414 Fissure, posterior, 43 Fittest, survival of, 16, 34 Flabellum, 359, 360, 362, 363, 366 Folds, pleural, 410, 414 Function of auditory organ, double, 358 Funt"ion of lateral line sense-organs, 357 Funt"ion of nerves, 448 Funt"ion of thyroid, 212, 215 Fusion of ganglia, 52 Galeodes, 230 Gale"des, brain, and camerostome, 222, 223 Gale"des, primordial cranium, 341 Gale"des, racquet-organs, 369, 375 Ganglia, infraœsophageal, 4, 12, 14, 51, 221 Ganl"ia, supraœsophageal, 4, 12, 14, 49, 52, 221, 225 Ganl"ia, origin of, of cranial and spinal nerves, 281 Ganglion, epibranchial, 164, 282 Ganl"ion, habenulæ, 48, 78 Ganl"ion, optic of retina, 72, 89, 97 Ganl"ion, of posterior root, 466 Ganl"ion, cells of sympathetic system, 424, 428, 448 Ganoids, 23, 345 Gastrula theory, 165, 459 Genital corpuscles, 470 Geological record, 20 Geol"gical strata, 22 Geotria australis, 80 Germ-band, 482 Germ-cells, 471 Giant-fibres, 489 Gigantostraca, 25, 234 Gills, 148, 161, 185, 214, 494 Glabellum, 339 Glands, carotid, 427 Gla"ds, coxal, 242, 246, 319, 321, 425, 429 Gla"ds, ductless, 418 Gla"ds, generative, of Limulus, 209 Gla"ds, internal secretion of, 214 Gla"ds, lymphatic, 418 Gla"ds, pineal, 15, 63, 75, 456 Gla"ds, pituitary, 244, 246, 319, 425 Gla"ds, segmental, of Crustacea, 422 Gla"ds, submaxillary, 466 Gla"ds, sweat, 448 Gla"ds, thymus, 425 Gla"ds, thyroid, of Ammocœtes, 193, 194, 196, 201, 205, 429 Gla"ds, tissue round brain of Ammocœtes, 209, 379 Gla"ds, uterine, of Scorpion, 202, 203, 204, 205 Gnathostomata, 60, 343 Goblet, 359, 360, 373 Goitre, 215 Gonad, 475, 479 Gonocœle, 475, 481 Grooves, ciliated, 188, 197, 212 Gro"ves, hyper-pharyngeal of Amphioxus, 410 Gro"ves, ventral, of apus and trilobites, 436 Gymnophiona, 393 Hæmocytes, 472 Head of embryo dogfish, 121, 123 Head-shield, dorsal, of Ammocœtes, 330, 331, 338 Head-s"ield, dor"al, of Auchenaspis, 29, 31, 338 Head-s"ield, dor"al, of Cephalaspis, 327, 328, 330, 338, 348 Head-s"ield, dor"al, of Cyathaspis, 340 Head-s"ield, dor"al, of Didymaspis, 338 Head-s"ield, dor"al, of evidence of segmentation, 339 Head-s"ield, dor"al, of Keraspis, 328 Head-s"ield, dor"al, of Ostreostraci, 327, 348 Head-s"ield, dor"al, of Palæostracan, 348 Head-s"ield, dor"al, of Pteraspis, 29 Head-s"ield, dor"al, of Thyestes, 29, 31, 327, 332, 338, 340, 341, 348 Head-s"ield, ventral, Scaphaspis, 349 Heart, nerves, 2, 447 Her"t, origin of vertebrate, 179, 451, 459 Her"t, relative position in vertebrate and invertebrate, 175 Her"t, veins forming vertebrate, 180 Hemiaspis, 24, 25, 249, 250, 351, 414 Hemispheres, cerebral, 47 Hepatopancreas of Ammocœtes, 452 Hepatop"ncreas of Limulus, 211 Heterostraci, 29, 275, 326, 343 Hirudinea, 478 Histolysis in transformation of the lamprey, 59 Homology of branchial region of vertebrate and invertebrate, 149 Homol"gy of ductless glands and nephridial organs, 418 Homol"gy of external genital ducts of arthropods and nephridia of annelids, 429 Homol"gy of germinal layers in all Metazoa, 459 Homol"gy of pituitary body of Ammocœtes and coxal glands of Limulus, 319 Homol"gy of tubular muscles of Ammocœtes and veno-pericardial muscles of Limulus, 309 Homol"gy of ventral aorta of vertebrate and longitudinal venous sinuses of Limulus, 178 Hydra, 441, 465, 472, 476 Hydrophilus larva, eye, 84 Hyoid segment in Ammocœtes, 186, 267 Hypoblast, 434, 438, 444, 445, 459 Hypoctonus, cartilage cells in entosternite, 133 Hypo"tonus, operculum, 189, 207 Hypogastric plexus, 3 Hypogeophis, 393 Hypophysis, 229, 244, 317, 318, 340 Infundibulum, position, 122,132 Infun"ibulum, tube, the ancestral œsophagus, 4, 37, 244, 318 Infun"ibulum, tu"e, relation to neural canal, 14, 36, 318, 440, 457 Infun"ibulum, tu"e, relati"n to notochord, 318, 435,440 Infun"ibulum, tu"e, relati"n to olfactory tube, 220, 228, 318, 340 Insects, chordotonal organs, 364, 370 Invertebrate, heart, 175, 179 Invert"brate, excretory organs, 418 Invert"brate, nervous system, 13, 54 Invert"brate, segmental nerves, 152 Keraspis, 75, 328, 338 Kidney, 420, 459, 476 Kid"ey, nerves, 477 King-crab, v. Limulus Labyrinthodont, 21, 28 Lamina terminalis, 49 Lamprey, v. Ammocœtes and Petromyzon Larva, v. Transformation of the Lamprey Lateral line system, 261, 355, 411, 470 Law of Progress, 19 Lw" of Recapitulation, 434, 456, 498 Layer, germinal, 459 Lay"r, laminated, 347, 348 Leech, 421 Lens, formation, 83, 115 Lepidosiren, 148, 461, 466 Limulus or king-crab, 25, 140, 236, 240 Liml"us appendages, branchial, 138, 164, 175 Liml"us appendages, prosomatic, 381 Liml"us brain, 54 Liml"us circulation, 174, 176 Liml"us classification, 26, 249 Liml"us cœlomic cavities, 252, 328 Liml"us coxal glands, 321, 389, 397, 403, 429 Liml"us eyes, median, 62, 74, 81 Liml"us entosternite or plastron, 142, 143 Liml"us flabellum, 360, 362, 363, 380, 381 Liml"us generative organs and ducts, 189, 202, 208, 209, 380 Liml"us heart, 180 Liml"us musculature, branchial, 170 Liml"us muscl"ature, prosomatic, 247 Liml"us muscl"ature, veno-pericardial, 177, 297, 309, 313 Liml"us nerves, appendage, 140, 157 Liml"us ner"es, cardiac, 314 Liml"us ner"es, segmental, tripartite division of, 157, 235, 267, 355 Liml"us segments, branchial, 152 Liml"us segm"nts, first mesosomatic, 188 Liml"us segm"nts, prosomatic, 233 Liml"us operculum, 189, 202, 235, 295 Liml"us sense-organs, poriferous, of appendages, 359 Lip, lower, of Ammocœtes, 246, 289, 297, 458 Li", upper, of Am"ocœtes, 228, 243, 303, 336 Liver, Ammocœtes, 452 Liv"r, Limulus, 209, 211 Lizard, pineal eye, 80 Liz"rd, suprarenals, 424 Liz"rd, tail, 50 Lobes, optic, 101 Lobster, 489 Lungs, 148 Lung-books of scorpions, 150 Lymph, 474 Lymph-corpuscles, 463, 490 Lymphocytes, 472 Malapterurus, 470 Mammal, dominance of, 21 Man, dominance of, 17 Marsipobranchs, 23, 35 Medullation of nerve-fibres, 20, 267, 467, 477 Membranes, basement, 436 Meroblastic egg, 485 Merostomata, 25, 249, 321 Mesencepalon, 48 Mesoblast, 444, 455, 459 Mesoglœa, 474 Mesonephros, 389, 400, 424, 429 Mesosoma, 52 Mesothelium, 472, 477 Metanephros, 389 Metasoma, 52, 387, 411 Metastoma, 239, 246, 272, 289, 342, 458 Metazoa, 444, 459, 471, 472 Meynert's bundle, 48, 77 Mollusca, dominance of, 23 Mouth, old, or palæostoma, 14, 317, 322, 440, 458 Mo"th, vertebrate, 317 Muco-cartilage, v. Cartilage Muscles, antagonistic, 447 Mus"les, branchial, 170 Mus"les, connection of, with central nervous system, 464 Mus"les, eye, and their nerves, 263 Mus"les, prosomatic, 243, 247 Mus"les, phylogeny of origin of skeletal, 478 Mus"les, rudimentary, in Ammocœtes, 289 Mus"les, somatic trunk, origin of, 406 Mus"les, striated, 20, 155 Mus"les, tubular, of Ammocœtes, 309 Mus"les, unstriped, 20, 447, 491 Mus"les, visceral and parietal, 155, 172 Mus"les, veno-pericardial of Limulus and Scorpion, 177, 297, 309 Muscle-spindles, 267 Mygalidæ, stomach, 109 Mygl"idæ, segmentation, 249, 306 Myomeres, 262, 337, 414, 479 Myotomes, 332, 337, 338, 391, 407, 408 Mysis, eyes, 100 My"is, ductless glands, 422 Myxine, 220, 392, 402, 419 Nebalia, 144, 422 Nemertina, 475 Nephridia, 395, 421, 429 Nephrocœle, 430 Nephrotome, 393 Nerves, abducens, 155, 263, 266 Ner"es, auditory, 356, 376 Ner"es, autonomic, 3 Ner"es, facial, 155, 156, 186, 188, 192, 311, 356, 378 Ner"es, fa"ial, ramus branchialis profundus, 311 Ner"es, to flabellum, in Limulus, 361, 375 Ner"es, glossopharyngeal, 155, 156, 186, 356 Ner"es, hypoglossal, 156 Ner"es, inhibitory, 447 Ner"es, inedullation of, 20, 267, 467, 477 Ner"es, occulomotor, 155, 234, 263, 274 Ner"es, olfactory, 229 Ner"es, optic, 101, 104 Ner"es, ot"ic, of pineal eye, 79 Ner"es, origin of ganglia of cranial and spinal, 281 Ner"es, to pecten of Scorpion, 375, 376 Ner"es, preganglionic, 2 Ner"es, of prosoma in Limulus, 235, 355 Ner"es, regeneration of, 469 Ner"es, roots, of Limulus, 157 Ner"es, sacral, 448 Ner"es, segmental, 152, 156 Ner"es, segmental nature of cranial, 259, 411 Ner"es, spinal, absence of lateral roots in, 388 Ner"es, spinal accessory, 154 Ner"es, trigeminal, 151, 155, 156, 234, 243, 257, 279 Ner"es, trigm"inal, motor nucleus of, 280 Ner"es, trigm"inal, of Ammocœtes, 288 Ner"es, tripartite arrangement of cranial nerves, 154, 157, 235, 267, 355 Ner"es, trochlear, 48, 155, 234, 263, 276 Ner"es, vagus, 151, 154, 156, 173, 186, 356, 447, 449 Nervous system, central, comparison of Vertebrate and Arthropod, 36, 457 Nervous "ystem, ce"tral, connection of, with muscular and epithelial tissues, 464 Nervous "ystem, ce"tral, conne"tion of, with retina, 71 Nervous "ystem, ce"tral, disease of, 50 Nervous "ystem, ce"tral, evidence of, 8 Nervous "ystem, ce"tral, evolution of, 34 Nervous "ystem, ce"tral, importance of, 16, 463, 482, 498 Nervous "ystem, ce"tral, invertebrate, 10, 13, 54 Nervous "ystem, ce"tral, origin of, 480 Nervous "ystem, ce"tral, relation of germ-band to, 483 Nervous "ystem, ce"tral, segmentation of vertebrate, 51 Nervous "ystem, ce"tral, tube of, 36-51, 102, 211, 433, 455, 457 Nervous "ystem, ce"tral, vertebrate, 10, 13, 40, 41, 152 Nervous "ystem, enteric, 447 Nervous "ystem, sympathetic, 2, 424, 428, 448, 491 Neurenteric canal, 37 Neuroblast, 465 Neuromeres, 55, 247, 262, 312, 316 Neurones, 72, 92, 465 Neuropil, 71, 91 Neuropore, 220, 457 Nose, 219 No"e, of Osteostraci, 329, 352, 458 Notochord, 120, 122, 180, 181, 220, 244, 295, 318, 405, 417, 433, 436, 494 Ocelli, 70 Œsophagus of Ammocœtes, 405 Œsop"agus of Arthropod, compared to tube of infundibulum, 4, 244, 440 Olfactory apparatus, evidence of the, 218 Olfa"tory organs of the Scorpion group, 220 Olfa"tory tube of Ammocœtes, 219, 225, 244, 317 Oligochæta, 421, 478 Operculum of Eurypterus, 191, 212, 291 Operc"lum of Limulus, 189, 202, 235, 295 Operc"lum of Phrynus, 191 Operc"lum of Scorpion, 189, 206, 212, 372 Operc"lum of Thelyphonus, 189, 190, 206 Organs, arrangement of, 10 Org"ns, auditory, of arachnids and Insects, 368 Org"ns, branchial, innervation of vertebrate, 151 Org"ns, bran"hial, sense-organs of embryo vertebrate, 261, 281 Org"ns, chordotonal, of insects, 364, 369, 370 Org"ns, electric, 470 Org"ns, generative, of Limulus, 208, 209 Org"ns, gener"tive, connection between Thyroid gland and, 215 Org"ns, genital, of sea-scorpions, 206 Org"ns, lateral line, 355, 411 Org"ns, lyriform, of arachnids, 364, 369 Org"ns, olfactory, of Scorpion group, 220 Org"ns, phagocytic, 420 Org"ns, racquet, of Galeodes, 369, 375 Org"ns, segmental excretory, 389, 391, 408, 418, 459, 477 Org"ns, sense, of appendages of Limulus, 358 Org"ns, vestigial, 456 Org"ns, of vision, evidence of, 68 Org"ns, vital, 57 Origin of alimentary canal, 444 Ori"in of arthropods from annelids, 395 Ori"in of atrial cavity, 409 Ori"in of auditory capsules and parachordals, 377 Ori"in of cœlom, 475, 481 Ori"in of ductless glands, 428 Ori"in of free cells, 472 Ori"in of heart of vertebrate, 179 Ori"in of lateral line organs, 356 Ori"in of muscles, 478 Ori"in of musculature, branchial, 170 Ori"in of muscul"ture, somatic trunk, 406 Ori"in of nervous system, central, 480 Ori"in of notochord, 434 Ori"in of segmental excretory organs, 389 Ori"in of skeleton of vertebrates, 119 Ori"in of vertebrates, 9, 36, 351, 433, 493 Ostracodermata, 326, 343 Osteostraci, 29, 75, 275, 326, 343 Otoliths, 378 Ovum, 473 Pacinian bodies, 470, 477 Palæmon, 20, 422 Palæontology, evidence of, 20, 497 Palæostoma, 317 Palæostraca, 27, 396 Palæo"traca, median eyes, 74 Palæo"traca, mesosomatic appendages, 188 Palæo"traca, olfactory organs, 221 Palæo"traca, segments, compared to Ammocœtes, 308 Pantopoda, glands, 423 Parachordals, 121, 132, 377 Parapodia, 357 Parapodopsis, foot glands, 422 Parathymus, 427 Parathyroids, 427 Parietal organ, 76 Pecten of scorpion, 114, 359, 366, 371, 372, 373, 374 Pedipalpi, 190 Periblast, 471 Peripatus, 396, 399, 400, 411, 421, 429 Petromyzon, alimentary canal, 405, 445 Petro"mzon, auditory organ, 378 Petro"mzon, branchial segments, 169 Petro"mzon, life-history, 59 Petro"mzon, olfactory tube, 219, 226 Petro"mzon, pronephric duct, 402 Petro"mzon, retina and optic nerve, 95 Petro"mzon, skeleton, 125 Petro"mzon, suctorial apparatus, 287, 304 Petro"mzon, transformation, v. Transformation of the Lamprey Phagocytes, 420, 471 Pharynx of Amphioxus, 410 Phar"nx of Vertebrate, 440 Phoronis, 439 Phrynus, brain, 53 Phry"us, caudal brain, 450 Phry"us, carapace and carapace removed, 250 Phry"us, cœcal diverticula, 109 Phry"us, evidence of segmentation of carapace, 249, 250, 341 Phry"us, operculum, 191 Phry"us, prosomatic appendages, 306 Phry"us, crossing of dorso-ventral muscles, 271, 277 Phry"us, stridulating apparatus, 368 Phyllodoce, 395 Phyllopoda, 321 Pigment, in Ammocœtes, in position of atrial cavity, 412 Pigm"nt, in epithelial lining of central nervous system, 43, 457 Pigm"nt, in choroid of vertebrate eye, 104, 107 Pigm"nt, in between glandular cells round brain of Ammocœtes, 211, 379 Pigm"nt, in tapetal layer of retina, 70 Pigm"nt, in white, of right pineal eye of Lamprey, 76, 80 Pineal body, 14, 15 Pin"al eyes, 74, 233, 244 Pin"al ey"s, of Ammocœtes, 80, 78, 85 Pin"al gland, 63, 75, 456 Pits, epithelial, of diaphragms in Ammocœtes, 164 Pi"t, epith"lial, of skin in Ammocœtes, 173, 200 Pituitary body, 244, 246, 319, 321, 425, 430 Plasma-cells, 471 Plakodes, 283 Planarians, 475 Plastron, formation of cranial walls from the, 86, 322, 341 Plat"ron, of Limulus, 136, 142, 143 Plat"ron, Palæostracan, compared to trabeculæ of Ammocœtes, 145, 377 Plat"ron, muscles attached to the, 270 Plat"ron, of Thelyphonus, 143 Platyhelmia, 475 Pleuron, 410, 415 Plexus, of Auerbach, 447 Plex"s, of choroid, 38, 45, 49, 103 Plex"s, of hypogastric, 3 Polychæta, 357, 395 Pores, abdominal, 430 Porifera, 473 Pouch, formation of gill, 165, 166 Prestwichia, 24, 25, 249, 351 Principle of concentration and cephalization, 51 Prini"ple of embryology, 455 Pristiurus, 424 Progress, law of, 19 Progr"ss, result of, 56 Pronephros, 389, 397, 419, 424, 449 Prosencephalon, 48 Prosoma, 52 Protopterus, 148 Protostraca, 27, 396, 417 Proto"traca, dominance of, 28 Protozoa, 166, 479 Pseudoniscus, 25, 249 Pteraspis, 29, 30, 275, 326, 343, 344, 350 Pterichthys, 29, 31, 239, 326, 351 Pterygoid, pedicle of, 295 Pterygotus, 25, 27, 56, 170, 191, 221, 235, 238, 249, 276 Ptychodera, 494, 495 Ramus branchialis profundus of facial nerve, 311 Ra"ms communicans, 2, 3 Raphe, 46 Recapitulation, law of, 434, 456, 498 Regeneration of nerves, 469 Reptiles, dominance of, 21 Retina, compound, 71 Ret"ia, development of, 101 Ret"ia, inversion of, in Vertebrates, 114 Ret"ia, inverted, 70 Ret"ia, layers of compound, 73 Ret"ia, lay"rs of in Crustacean eye, 100 Ret"ia, of lateral eye of Ammocœtes, 93, 95, 111 Ret"ia, Musca, 89 Ret"ia, Pecten and Spondylus, 114 Ret"ia, upright compound, 72 Ret"ia, upri"ht simple, 69 Rhabdites, 69, 81 Saccus vasculosus, 244, 322 Scales, 345 Scaphaspis, 349 Schwann, sheath of, 469 Sclerotomes, 388 Scorpion, brain, 54 Scor"ion, branchial lamellæ, 175 Scor"ion, development, 482 Scor"ion, entochondrites, 377 Scor"ion, excretory organs, 397 Scor"ion, eyes, 75 Scor"ion, lung-books, 150, 170 Scor"ion, lymphatic glands, 423 Scor"ion, muscles, oblique, 278 Scor"ion, mus"les, recti, 271 Scor"ion, mus"les, respiration, 171 Scor"ion, mus"les, veno-pericardial, 177 Scor"ion, muscular system, 247, 268, 269 Scor"ion, nerves to Cheliceræ, 237 Scor"ion, olfactory organs, 220 Scor"ion, operculum of male, 189, 206, 212 Scor"ion, pecten, 359, 366, 371, 373, 374, 377 Scor"ion, under surface, 372 Scor"ion, uterus, 189, 202, 203, 204, 205, 212 Sea-scorpions, 25, 26, 27, 56, 150, 170, 191, 208, 221, 232, 235, 241, 349, 359 Segmentation, branchiomeric, 124 Segmet"ation, body-muscles in vertebrate, 388 Segmet"ation, eye-muscles, 248 Segmet"ation, of head, double, 155, 157, 173, 234, 258, 411, 459 Segmet"ation, of head-shield, 339 Segmet"ation, history of cranial, 258 Segments, branchial of Ammocœtes, 161, 178, 186 Segm"nts, hyoid, in Ammocœtes, double, 186, 201, 267, 300 Segm"nts, innervation of branchial, 151 Segm"nts, first mesosomatic, in Limulus and its allies, 188 Segm"nts, mesosomatic, of Eurypterus, 192 Segm"nts, prosomatic of Limulus and its allies, 233, 249 Segm"nts, prosm"atic of Ammocœtes, 286 Segm"nts, of spinal region of Vertebrates, 388 Segm"nts, of trigeminal nerve-group, 257, 279 Segm"nts, tubular muscles of hyoid, 299 Sense-organs of Amphioxus, 34 Sense-o"rans of branchial, of Limulus, 359, 360 Sense-o"rans of lateral, of Annelids, 357, 367 Sense-o"rans of lateral-line system, 356, 411, 470 Serum, 492 Significance of the optic diverticula, 102 Silurus, 488 Sinus, longitudinal venous, of Limulus, 176, 312, 451 Sin"s, rhomboidal of bird, 46 Skeleton, Ammocœtes, 126, 296, 335 Skel"ton, Amm"cœtes, branchial, 126, 126 Skel"ton, Amm"cœtes, basi-cranial, 132 Skel"ton, Amm"cœtes, muco-cartilaginous, 291, 296, 330, 331 Skel"ton, aponeurotic, 414 Skel"ton, Cephalaspis, 414, 415 Skel"ton, evidence of the, 119 Skel"ton, Limulus, cartilaginous, 126, 136 Skel"ton, Lim"lus, mesosomatic, 137 Skel"ton, Lim"lus, prosomatic, 142 Skel"ton, Petromyzon, 125 Skel"ton, Vertebrate, commencement of bony, 120, 121 Skin, digestive power of cells of, in Ammocœtes, 58, 442 Si"n, of Ammocœtes, 346 Si"n, nerves of, 448 Skull of dogfish, 123 Skl"l of pig-embryo, 121 Slimonia, 27, 56, 170, 235, 238, 249, 276, 303 Solenocytes, 395, 477 Solpugidæ, 109 Sphæroma serratum, brain, 62, 90, 101, 225 Spiders, eyes, 75 Spi"ers, stomach, 109 Spina bifida, 50 Spinal cord, difference between brain and, 45 Spi"al cr"d, region of, 385 Spi"al cr"d, termination in bird-embryo, 51 Spondylus, retina of, 114 Squilla, eyes, 100 Sqi"lla, glands, 422 Stomach, cephalic, 4, 43, 102, 244 Stylonurus Lagani, 27, 235, 239, 249 Substantia gelatinosa Rolandi, 44 Suprarenal body, 423 Surfaces, dorsal and ventral, 11 Surf"ces, reversal of, 15, 29, 36, 87, 175, 352, 433, 484 Synapse, 72 Syncytium, 464, 471, 479 Tail of lizards, 50 Tapetum, 69 Teleosteans, 23, 345, 420, 424 Tendon-organs, 470 Tentacles of Ammocœtes, 246, 289, 303 Tergo-coxal muscles, 247 Test, biological, of relationship of animals, 492 Thalainencephalon, 48 Thelodus, 344 Thelyphonus, 231 Thely"honus, brain, 53, 54, 56, 224 Thely"honus, br"in, caudal, 450 Thely"honus, cœcal diverticula, 109 Thely"honus, entosternite, 143 Thely"honus, genital organs, 206 Thely"honus, lyriform organs, 368 Thely"honus, olfactory passage, 226, 306 Thely"honus, operculum, 189, 190, 206, 207 Theory, gastræa, 444, 461 Theories of the origin of vertebrates, 9, 411, 433, 457 Thionin reaction, 131, 139, 213, 330, 336 Throat, formation of, 179 Thyestes, 30, 31, 275, 326, 328, 329, 339, 340, 341 Thymus, 425, 430 Thyroid gland of Ammocœtes, 61, 127, 192, 194, 196, 429, 459 Thyr"id gl"nd evidence of the, 185 Thyr"id gl"nd function of, in Ammocœtes, 213 Tissues, connective, 471, 474, 481 Tiss"es, evolution of, 19 Tiss"es, notochordal, 435 Tiss"es, two groups of, 463 Tongue of Ammocœtes, 246, 303 Tonsils, 427, 430 Torpedo, 262, 392, 470 Trabeculæ, 121, 132, 133, 145, 277, 295, 377 Transformation of the Lamprey, 18, 35, 59, 61, 125, 168, 193, 199, 200, 220, 227, 228, 287, 291, 304, 307, 309, 331, 336, 347, 349, 389, 445 Tremataspis, 32, 75, 275, 326, 351, 352 Trilobites, 24, 25, 26, 437 Trilo"ites, appendages, 351, 437 Trilo"ites, diagram of section through a trilobite-like animal, 413 Trilo"ites, dominance of, 26 Trilo"ites, excretory organs, 396 Trilo"ites, eyes, 74, 88 Trilo"ites, glabellum, 339 Trilo"ites, relations of, 249, 283 Trilo"ites, respiratory apparatus, 170 Trilo"ites, ventral surface, 437 Tube of central nervous system, 37, 38, 42, 102, 211, 433, 455, 457 Tu"e from IVth ventricle to surface of brain in Ammocœtes, 209 Tu"e Fallopian, 431 Tu"e hypophysial, 229, 244, 317, 440 Tu"e meeting of four tubes in vertebrate, 318, 440 Tu"e notochord originally a, 436, 440 Tu"e olfactory, of Ammocœtes, 219, 225, 317, 440 Tu"e unsegmented, in segmented animal, 439 Tunicata, 16 Tuni"ata, budding of, 441 Tuni"ata, degeneration, 12, 17, 19, 60 Tuni"ata, endostyle, 198, 212 Tuni"ata, hypophysis, 425 Tuni"ata, notochord, 438 Tuni"ata, position of, 494 Unit, appendage, in non-branchial segments, 185 Ui"t, branchial, 161, 165, 168, 185 Ureters, nerves of, 448 Uterus of Scorpion group, 189, 202, 203, 204, 205, 214 Utr"us vertebrate, nerves of, 448 Valve, ileo-colic, 449 Val"e, of Vieussens, 48 Variation in dominant races, 21, 88 Vari"tion meristic, in spinal nerves, 154, 387 Veins, forming vertebrate heart, 180 Velum, 228, 289, 298, 302 Vertebrates, alimentary canal, innervation of, 446 Verte"rates, atrial cavity, 410 Verte"rates, auditory apparatus and lateral-line system, 356 Verte"rates, body-cavity, 401, 430 Verte"rates, brains, 40 Verte"rates, branchial organs, 151 Verte"rates, cœlomic cavities in head region, 251, 266 Verte"rates, cranium, evolution of, 342 Verte"rates, egg of, 483 Verte"rates, evolution of, 11 Verte"rates, excretory organs, 389, 391, 408 Verte"rates, glands, ductless, 418 Verte"rates, gla"ds, internal secretion of, 215 Verte"rates, heart, 175, 179, 180 Verte"rates, muscles, evidence of segmentation of eye, 248 Verte"rates, mus"les, oblique, 278 Verte"rates, mus"les, origin of somatic trunk, 406 Verte"rates, nervous system, central, 13 Verte"rates, nerves, segmental, 152 Verte"rates, notochord and gut, 434 Verte"rates, organs of, 10 Verte"rates, origin of, 9, 411, 433, 457 Verte"rates, segments, prosomatic, 257 Verte"rates, skeleton, commencement of bony, 120, 458 Verte"rates, spinal cord and medulla oblongata, 44 Verte"rates, spinal region, 385 Verte"rates, thyroid, connection between generative organs and, 215 Verte"rates, tubes, meeting of four, 318, 440 Vesicles, cerebral, formation of, 48, 458 Vitellophags, 471, 483 Volvox, 479 Wolffian body, 390 Xiphosura, 24, 26, 249 Yolk, 482