Figure 227. — Blood from heart of chick embryo. Incubation age, 5 days 21 hours. 1,370 X. 



1-12 Mature primary erythrocytes ranging in size from 

 large (5) to small (9 and 10). 



13-15 Mid-polychromatic erythrocytes of later embryonic 

 red-cell generations. 



16-18 Late polychromatic erythrocytes of later embry- 

 onic red-cell generations. Cell 17 is at the transi- 

 tion between mid- and late polychromatic stages. 



19-24 



25 



26 

 27 



28 



Late polychromatic erythrocytes in which the 

 artifacts of cytosomal fracturing are present. 

 Early polychromatic erythrocyte in mitosis, prob- 

 ably an early anaphase. 



Erythroblast of later embryonic cell generations. 

 Medium embryonic thrombocyte. 

 Small embryonic thrombocyte. 



100 



