INDEX 



497 



Visceral peritoneum, 30, 94 

 Visceral skeleton, 56 

 Vitalism, 12 

 Vitamins, 109-111 

 Vitelline membrane, 244 

 Vitreous humor, 194 

 Viviparous, 154, 162 

 Vocal cord, 35 

 Vocal sac, 30 

 Volvox, 368, 369 

 Vomerine teeth, 29 

 Vorticella, 383, 384 



Wharton's duct, 94 

 Whitefish, 449 

 Wild boar, 296 



X 



X chromosome, 232, 234, 275, 276 

 Xenopsylla, 432 

 Xiphisternum, 67 

 Xiphosura, 422 



W 



Walking stick, 335, 429 

 Wallaby, 358 

 Warmth receptors, 188 

 Warning adaptations, 337, 338 

 Wasps, 356, 432 



wing muscle, 92 

 Water, 45 



environment, 359 

 Water vascular system, 436 

 Weapons, 328-332 



Y chromosome, 232, 234, 275, 276 

 Yolk, 237 

 Yolk plug, 248 



Z 



Zoogeography, 3 



ZOOMASTIGOPHORA, 370 



Zygapophyses, 61 

 Zygote, 154 

 Zymogen, 105, 106 



