INDEX 



839 



Veins, 213, 221 

 valves of, 222 

 Vena cava, 248, 249 



Venom. 721. 722 



Ventricles, 218, 700, 701 



Venus's flower basket. 458 



Venus's girdle, 493 



Vertebra, 141, 672, 686 



Vertebral column, 140, 143, 662, 672 



Vertebrata, 141. 664-680, 798 



probable relationships of, 663 

 Vertebrate body plan, 146, 147 



compared with invertebrate, 667 



generalized, 669 

 Vespa, 312 

 Villard, 12 

 Villi, 192, 193 

 Vinegar eels, 520, 522 

 Viruses, 25, 397 

 Vitamins, 32, 168, 170-172 



A group, 171, 172, 174, 324, 329 



B group, 171, 173 



Bi.., 171, 204 



C group, 171 



D group, 171, 731 



E, 171 



K, 171, 191, 212 

 Vitreous humor, 326, 327 

 Viviparous animals, 359 

 Vocal cords. 182, 206, 240, 241, 689 

 Voice. 240. 703, 720 

 Volvox. 426, 428, 433, 434 

 Vomerine teeth. 694 

 Vorticella, 428, 448 



Weasel, 183 



Welk, 631 



Whale, 3, 32, 52, 129, 764, 767 



blue, 69. 70 



development of flipper, 782 



sperm, 767 



voice. 240 

 Whale shark, 70 

 Whalebone, 766, 768 

 Whipple. G. H., 204 

 White-bellied swallow, section through 



head. 324 

 Whitney. D. D., 543 

 Wilson. E. B.. 406 

 Wings. 740, 741, 782 

 Wishbone, 694. 739, 740 

 Woodpecker, 176 

 Woodruff, L. L., 333 

 Worker bees, 612, 614, 616 



"dances," 620, 621 



legs of, 615 



special structures of, 615, 616 

 Wuchereria bancrojti, 528, 529 



X-rays, 12, 410 

 Xanthophyll. 56 

 Xenarthra, 762, 799 

 Xerophthalmia, 174 

 Xiphosura. 623 

 Xylem, 59-61, 63 



W 



Wald, G., 324, 325 



Wallace, A. R., 791 



Walrus. 764 



Wutasenia scintillans, 649 



Water. 4. 13-16, 27, 81, 198, 226, 227 



in frog, 703 



need of, 3, 63, 65, 80, 168, 195, 197, 555 

 Water cycle, 80 

 Water molecules, 20 

 Water striders, 20 

 Wax pick, 616 



Yawn, 241 

 Yolk, 368 

 Yolk sac, 380, 668 

 Yucca lily, 94, 96 

 Yucca moth, 94 



Zoea, 575, 578 

 Zooflagellates, 432, 434 

 Zoology, 4 

 Zoraptera, 593 

 Zygote, 47, 444, 447 



