Index 



887 



Urodeles, serologic relationships in, 107, 108 

 Utriculus, 475, 517 



Vacuoles, contractile, in Protozoa, 38 

 efficiency of, 46 

 function of, 40 

 mechanism of filling, 44 

 food, in Protozoa, 150, 155 

 Vagus nerve, effect on gastric section, 1 56, 

 157 

 effect on heart, 557 

 Vahlkampt^a calkensi, contractile vacuole 



in, 42 

 Valine, structural formula, 118 

 Vanadium chromogen, 292, 293 



as blood pigment, 305 

 Vanadocytes, 305 



Ventilation in polychaete worms, 262 

 Ventilation lungs, 220 

 Venus, calcium in, 97 



effect of acetylcholine on heart of, 560 

 muscle in, 579 

 osmotic adjustment in, 13 

 Vertebrates, blood protein concentration 

 in, 104 

 brain in, various types, 829 

 cardiac rhythm in, 546 

 chemoreception in, 453 



behavior and, 456 

 cholinergic systems in muscles in, 609 

 chroma tophores in, 681, 703 

 control of secretion in, 156 

 cutaneous respiration of, 212 

 equilibrium orientation in, 520 

 eye in, 393-405 

 fat digestion in, 177 

 gills in, 215 



growth in, hormones and, 726 

 hormones and sex and reproduction and, 



740 

 intermediary metabolism and hormones 



in, 756 

 ions in body fluids in, 80 

 kidney in, 48 

 labyrinth in, 516 

 locomorion in, spinal reflex control of, 



821-827 

 lower, carbon dioxide transport in, 332 

 marme, ions m body fluids in, 85 

 pH of digestive organs, 153 

 phonoreception by, 483 

 respiratory movements in, 254 

 site of digestion in, 151 

 See also Amphibians, Mammals, etc. 

 Vestibular nuclei, 831 

 Vestibule, 475 

 Vibration sense, 506 

 Viscosity of muscle, 602, 604 

 Vision, acuity of, 417 

 explanation of, 418 



Vision, aerial, 403 



air- and water-, 403 



aquatic, 402 



central mechanism of, 435 



color, 436-440. See also Color vision. 



dichromatic, 437 



functions, electrical measurement of, 

 422 



measurement of functions of, 414 

 by optic nerve discharge, 431 



nonphotochemical theories of, 418 



pattern, localized photoreceptors and, 

 387 



peripheral mechanism of, 405 



See also Eye and Photoreception. 

 Visual angle, 399 

 Visual field, 399 

 Visual purple. See Rhodopsin. 

 Vitamin(s), defined, 122 



fat-soluble, 131-135 



requirements of insects, 125 



water-soluble, 122 

 Vitamin A, 131 



in vision, 410 

 Vitamin Bi. See Thiamine. 

 Vitamin B^. See Riboflavin. 

 Vitamin Bg, 127 

 Vitamin Bn, 129 

 Vitamin C. See Ascorbic acid. 

 Vitamin D, 132 

 Vitamin E, 132 

 Vitamin K, 132 

 Vitamin P, 130 



Vitrification at low temperatures, 345 

 Volume, regulation of, in osmotic adjust- 

 ment, 13 

 in Protozoa, 38 



Warm-blooded animals. See Homoio- 



thernts. 

 Wasp, respiration during flight, 262 

 Water, 6-74 



avenues of entrance in Protozoa, 43 



balance, maintenance of, 6 



endocrine influences, 760 

 relation to nitrogen excretion, 201 



brackish, Crustacea in, 24 



content of tissues, osmotic concentra- 

 tion and, 8 



fresh, adaptation to, 33-38 

 crustaceans in, 29 

 osmoregulation of fish in, 47 



loss in insects, 56 

 in mammals, 59 



in temperature regulation, 366 



oxygen withdrawal from, 251 



poikilotherms inhabiting, 349 



salt. See Sea water. 



thermal properties of, 341 



vision in, 402 



