584 



INDEX 



Thomson, 552. 



Thorax, of crayfish, 322, 334; of 



locust, 344. 

 Thymus gland, 98. 

 Thyroid gland, 98, 99. 

 Thyroxin, 99. 

 Thysanoptera, 374. 

 Thysanura, 372. 

 Tibicen, 374. 

 Tissues, 140; contractile, 146; of 



earthworm, 301; epithelial, 140; 



nervous, 148; sustentative, 142. 

 Toad, 14, 15, 17, 20; classification of, 



12, 37. 

 Tongue, 44. 

 Touch, in earthworm, 302; in locust, 



360. 

 Toxopneustes, fertilization in, 232, 



233. 



Trachea, 63. 



Tracheae, 355. 



Trachelomonas, 156, 175. 



Tree frog, 16, 22, 28. 



Trematoda, 241. 



Trichodina, 254. 



Trichocysts, 177, 178. 



Trichomonas, 176. 



Tricoptera, 375, 379. 



Tri-hybridization, 469, 470. 



Trilobite, 503. 



Triploblastic body plan, 260, 281, 



308. 

 Trochelminthes, 238, 240, 241. 

 Trochophore, 313. 

 Tropisms, 181, 264, 318. 



Trypanosoma, 175, 209, 210. 



Trypsin, 85. 



Tsetse fly, in relation to sleeping 

 sickness, 209. 



Tubular glands, 142. 



Tubularia, 258. 



Tunicate, 13, 36. 



Turbellaria, 241, 452. 



Turtle, 37, 422, 423. 



Tympanic membrane, of locust, 348, 

 355; of man, 125. 



Tyndall, 204; apparatus of, 205. 



Typhlosole, 292. 



Undulating membrane, 175, 178. 

 Unicellular animals, see Protozoa. 

 Universal symmetry, 243. 

 Ureter, 47, 52, 403. 

 Urinary bladder, 52, 416. 

 Urino-genital system, of bird, 426; 



of frog, 51, 52. 

 Urochordata, 13, 36, 241. 

 Urodela, 12. 

 Uroglena, 196. 

 Uroleptus, 188. 

 Uropods, 323, 326. 

 Uterus, 433, 450, 451, 452. 



Variations, 5, 456, 486, 553, 559. 



Varieties, 13. 



Vas deferens, 283, 297, 358, 425. 



Vas efferens, 54, 297, 403. 



Vascular tissue, 143, 145, 146. 



Veins, 56; of frog, 57; of kidney, 

 53. 



Ventral nerve cord, see Nerve cord. 



Ventricles, of brain, 65, 66, 416; of 

 heart, 560. 



Ventriculus, 354. 



Vertebral column, 11. 



Vertebrata, 9, 10, 11; classification 

 of, 36, 37, 241. 



Vertebrates, appendages of, 20, 39, 

 498, 500, 501; body plan of, 49, 

 50, 246; circulatory system of, 56; 

 coelome and viscera of, 47; develop- 

 ment of, 397; environment of, 27; 

 external features of, 38; feeding 

 and food supply of, 31; inter-rela- 

 tions of species, 34; irritability of, 

 106; metabolism of, 71; morphol- 

 ogy of, 38; mouth cavity of, 42; 

 muscular system of, 68; natural 

 history of, 9; nervous system of, 

 63; organ-systems of, 50; physi- 

 ology of, 71, 106; respiratory 

 system of, 62; sensory-neuro- 

 muscular system of, 318; skeletal 

 system of, 68; skin and derivatives 

 of, 40; urino-genital system of, 51. 

 Vestigial organs, 530. 

 Villus, 87, 88, 150. 



