INDEX 



Wasps, social, 161. 



Water -beetle (illus.), 146; bug, 



giant (illus.), 141. 

 Whippoorwill (illus.), 203. 

 Woodpecker, Californian, feeding 



habit of (illus.), 128, 129. 



Xiphias gladius, metamorphosis 

 of (illus.), 99. 



Yellow-jacket (illus.), 162. 



Yolk, 80. 



Young, adaptations for defense of, 

 137 ; care of the, 250, 257 ; num- 

 ber of, 61. 



Zoea, 97. 



Zoogeography, 272. 

 Zoology, systematic, 64. 



(5) 



THE END 



