190 



W. B. CHAPMAN 



A Opdcd 









rJ}^- ^ ^^'"^'i'^'^ ^i^cida drawing of an operated chick of 90 hours incubation 

 (57 hours after operation). 



Fig. 9 A free-hand drawing of a chick of Ak days incubation in which the 

 breaking-up of the cai)illaries in the area pellucida is quite pronounced. Oper- 

 ated at 33rd hour of incubation. 



