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
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, 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, 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
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
Volvox, 479
Wolffian body, 390
Yolk, 482