706 INDEX 

 x 



Xenia hicksoni, 9 



Xenopus lavis.ZO sqq. Zacharjewsky, 497 sq., 503, 505 sq. 



Y Ziegler, 641 



Yak, 49 Zoarces, 151 

 Yolk-sac, 378 ; nutritive import- Zoth, 309 



ance of, 380 sqq. Zuntz, L., 68, 355 



Yule, 621 - E., 519 



Youatt, 334 

 Yung, 625 



Zweifel, 505 

 Zweifel and Abel, 346 



I'rilitetl by I'.AI.I.AXTYNK, HANSON & Co. 

 Kiliiiliurgh & London 



