INDEX 



Symphynota, 378 



Synapse, 96, 112. 113; in Hydra, 296 



Synapsis, 136 



Syncytia, in rotifers, 348 



Syngamy, 141 



Synthetic types, in evolution, 630 



Syphilis, 164 



Systemic arteries, 51 



Systemic veins, 51 



Tadpole larva, 159; of amphibians, 562; of 

 frog, 634; of green frog, 567; of Molgida, 

 547; of tunicates, 541 



Taenia pisiformis, 335, 336; T. saginala, 333, 

 340; T.' solium, 334, 336, 337, 338, 340 



Tail, 91; of spermatozoon, 137 



Tannns, 590 



Tapeworms, 332-340, 335, 336 



Tapir, 580 



Tarantula, 482 



Tarsiers, 591 



Tarstus, 585 



Tasmania, 425 



Tasmanian wolf, 609 



Taste buds, 48, 91, 110 



Taxonomy, 8, 217 



TCA cycle, see Tricarboxylic acid cycle 



Tectorial membrane, 108 



Teeth, 48, 70; of primitive birds, 574 



Telea, humidity and development of, 603 



Telencephalon, 87, 102, 103 



Telolecithal eggs, 146 



Telophase, 43 



Telson, 428 



Temperature, 91; and development of fruit 

 fly, 595; as environmental factor, 596-599; 

 decrease with increasing altitude, 600; ef- 

 fect on development, 159, 195; effect on 

 metabolic rate, 596; indirect effects of, 598; 

 optimum range, 597 



Temperature regulation, 125 126; in birds, 

 578, 598; in ectothermous animals, 597; 

 in mammals, 579, 598 



Ten-hooked larva, of Cestodaria, 333 



Tendons, 61, 68 



Tentacles, of hydra, 287 



Terehralulina, 363 



Teredo, 379 



Terminal filaments, 69, 96. 114 



Termites, 458, 475 



Terrapene, 567, 570 



Terrestrial animals, water relations of, 602 



Test, of Arbacia, 499, 500; of ascidians, 545 



Testes, 129 



Testis, of Hydra, 298 



Testosterone, 122 



Tetrabranchiata, 388 



Tetrad, 1.36, 138 



Tetraploid individuals, 206, 211 



letrapoda, 216, 541, 560 591 



Tetrasiemma, 341 



Thalassema, early development of, 144; fertili- 

 zation in, 145 



Thaliacea, 545, 550 



Theory, 5 



ITieory of Genie Balance, 210 



ITieory of Inheritance of Acquired Char- 

 acters, 646 



Theory of Natural Selection, 647 



llieory of Organic Evolution, 8, 655 



ITieorv of Preformation, 140 



Thermobia, 458, 459 



"ITiiamine, 32 



'ITioracic cage, 56, 80, 92 



Thoracic duct, 54, 77 



Thorax, 55, 92 



Thorny-headed worms, see Acanthocephala 



Thrombin, 64 



Thrombokinase, see Thromboplastin 



lliromboplastin, 64 



Thyone, 503, 504 



Thyroid gland, 95, 118 



llivrotropic hormone, 118 



ITiyroxine, 1 1 8 



Thysanura, 457, 458, 459 



Ticks, 480, 482 



Tiger, saber-toothed, 642 



Tiger beetles, 464, 466 



Time scale, of geologic periods, 617; of hu- 

 man evolution, 641 



Tineola, 469 



Ti.ssue culture, 16, 41 



Tissues, 10, 47, 58-70; of invertebrates, 510 



Toad, 541, 566 



Toadfish, 559 



Tocopherols, 32 



Tokophrya, 258 



Tongue, 48, 110 



Tools and weapons, of Stone Age man, 645 



Tooth shells, see Scaphopoda 



Tornaria larva, 539, 543 



Torpedo ray, 557 



Torsion, in gastropods, 384 



Totipotent cells, 139, 159; in Hydra, 292; in 

 oligochaetes, 412; in planarians, 322; in 

 regeneration, 530; in sponges, 276 



Touch, 91 



TPN, see Triphosphopyridine nucleotide 



Trachea, 55, 60, 119 



Tracheal gills, 455, 485, 517 



Tracheal system, of locust, 448, 449; of 

 onychophorcs, 483 



Tracheal sy.stems, of in.sect.s, 517; of inverte- 

 brates, 517; of spiders and scorpions, 482; 

 of terrestrial arthropods, 485 



Training, 199 



Transfer of cvsts, in Fjitamoeha histolytica, 

 237 



Translocation, 205 



Transport of food, 16-19 



706 



