886 



Index 



Temperature, respiratory quotient and, 276 



"sense" in insects, 357 

 Tenehrio, linoleic acid synthesis in, 134 



stereotropic orientation in, 508 

 Tension of saturation, 310 



oxygen, 244-254. See also Oxygen 



tension. 

 receptors, adaptation in, 512 

 surface, amoeboid movement and, 634 

 Tentacles as feeding mechanism, 145 

 Termites, digestion in, 172 

 Testis, effect of gonadotropins on, 741 

 estrogen production by, 746 

 hormones of, 743 

 Testosterone, structure of, 743 

 Tetrahymena, dietary factors of, 135 

 essential amino acids for, 117 

 substances needed for growth, 120 

 Thalamus, functions of, 834 

 Thermoreception in aquatic poikilotherms, 

 350 

 in insects, 358 

 in man, 364 

 in poikilotherms inhabiting moist air, 



353 

 in reptiles, 360 

 Thermoregulation. See Temperature regu- 

 lation. 

 Thiamine, requirements for, 122 

 Thiazole, requirements for, 123 

 Thigmotaxis, 507 



Threonine, structural formula, 118 

 Thresholds, sensory, 458 

 Thyroid gland, effect on metabolism, 238, 

 758 

 growth and, 727 

 in amphibians, 728 

 Thyroxin, effect on amphibians, 728 

 Tissues, body, ions in, 75 



soft, mechanisms for ingesting, 146 

 Tocopherol, 132 

 Tonus, muscle, 601 

 Torpedo, electric organs of, 617, 619 

 Touch, receptors of, 503 

 adaptation in, 510 

 sense of, 509 

 Trace eleitients, 94 

 Tracheae, 222 



respiratory control and, 267 

 Tracheole, 222 



Transmission, interneuronic, 789 

 after-discharge in, 805 

 inhibition in, 803 

 synaptic, 791 



acetylcholine and, 791 

 delay in, 799 

 electric current in, 796 

 ionic changes in, 795 

 refractory period in, 800 

 Transport in fluid-filled body spaces, 531 



Transport, intraceUular, 531 



mechanisms, extra-organismic, 531 

 morphological types of, 531 

 Tricarboxylic acid cycle, 269, 271 

 Trichocysts, 654 

 Trichoptera, gills in, 215 

 Trichosurus, motor cortex in, 837 

 Tritocerebrum, 818 

 Trimethylamine oxide, excretion of, 189 



in fish, 197 

 Tritanopia, 437 

 Trituration, 147 

 Tropism, 381 

 Tropotaxis, 386, 449 

 Trout, dietary factors of, 135 



phonoreception in, 485 

 Trypsin, 158 



distribution of, 164 

 Tryptophane, structural formula, 118 

 Tuhifex, hemoglobin function in, 321, 

 322, 323 



respiration in, 262 

 Tufts, branchial, 213, 214 

 Tunicates, peripheral nervous system in, 



810. See also Ascidians. 

 Tunicin, 305 



Turtles, blood and urine concentrations in, 

 58 



effect of acetylcholine on heart of, 560 



nitrogen excretion in, 198 

 Tympanic membrane, 473 

 Tympanic organs in insects, function, 495 



morphology of, 493 

 Tyramine, chromatophores in cephalopods 

 and, 690 



neuromuscular transmission and, 613 

 Tyrosine, structural formula, 119 



UcA, color changes in, 695, 701 

 UDH, 698 

 U/P ratio, 697 



Urea, excretion of, 188, 189, 198 

 in fish, 197 



in various animals, 192-196 

 production of, 201 

 Urease, distribution of, 203-205 

 Urechis, hemoglobin function in, 324, 



325 

 Ureotelic animals, 198 

 Uric acid, excretion of, 188, 189, 199 

 in aquatic vs. land animals, 198 

 in various animals, 192-196 

 formation of, 189 

 in body fluids, 200 

 Uricase, distribution of, 203-205 

 Uricotelic animals, 199 

 Urine, concentration of ions in, 93 



nitrogen in. See Nitrogen excretion and 

 Excretion. 

 Urodeles, phonoreception in, 487 



