DEVELOPMENT OF VESSELS WITHOUT HEART 



191 



Fig. 10 A camera lucida drawing of a section of the area pellucida of a chick 

 of 8 days incubation (7 days after operation) which shows small lakelets of blood 

 formed by the breaking-iip and retraction of the capillaries. Enl. 24 X. 



Fig. 11 Camera lucida drawing of capillary net in area opaca during eighth 

 day of incubation. Operated chick. Enl. 52 X. 



