INDEX 



441 



283; excretion of, 150, 151 ; in photo- 

 synthesis, 49; in respiration, 58 



Water birds, range of, 292 



Wax, glandular secretion, 154 



West Indies, submergence of, 318; union 

 with mainland, 318 



Wheat, fertilization in, 186 



White eye in Drosophila, 345 



Wichita-Clear Fork beds, 319 



Woodpecker, red-headed, range of, 292; 

 three-toed, range of, 292 



Workers (bees), 181 



Worms, classified, 272; fertilization in, 

 191, 194; hermaphroditism in, 190; 

 marine, birth stages, 202; parasitic 

 (see Parasitic worms) 



Wren, Carolina, range of, 292 



Xanthophyll, 49 

 X-body in Sagitta, 207 

 Xenophanes, 8 

 •Xiphosura, classified, 270 



Yellow-breasted chat, range of, 292 



Yolk, 214, 215 



Young, care of (see Parental care) ; devel- 

 opment at birth (see Birth stages); 

 methods of bearing, 194, 195, 196, 

 197, 198; no evolutionary sequence 

 in care of, 197, 198 



Yucca (see Pronuba yuccasella) 



Zoantharia, classified, 269 

 Zoanthidea, classified, 269 

 Zoogeography, 4, 6, 289-309; factors of, 



299; facts of, 289; methods of, 308; 



relation to ecology, 288, 309 

 Zoological sciences, 6, 12 

 Zoology, applications of, 24; definition 



of, 1 

 Zoonomia (Erasmus Darwin), 20 

 Zoothamnium, 87 

 Zygapophyses, 136 

 Zygospore, 176 

 Zygote, 174, 175 



