Figures 254-264. — Developmental stages of embryo erythrocytes following the primary generation, 

 often called secondary or definitive erythrocytes. 2,470 X. 



FinuRES 254-256: Enjlhroblasts. All from the same slide. 

 Embryo incuhaled 5 days 21 hours. 



254 Early erythroblast. 



255 Erythroblast. 



256 Late erythroblast. 



Figures 257, 258: Late erythroblasts or early polychromatic 

 erythrocytes in mitotic division. Embryos incubated 9 

 days 18 hours. 



257 Late anaphase. 



258 Late telephase. 



Figures 259-261: Erythroblasts showing various degrees of 

 failure of nuclear staining. All from the same slide. 

 Embryo incubated 5 days 3 hours. 



259 The nucleus has an empty appearance owing to its 

 incomplete staining. 



260 Slight .staining toward the right of the nucleus. 



261 Overall staining of the nucleus but not sufficiently 

 intense to be fully useful for cell identification. 



Figures 262-264: Early polychromatic erythrocytes. Same 

 slide as figures 359-361. 



262 The cytoplasm resembles that of the late erythro- 

 blast but the condensation of nuclear chromatin is 

 characteristic of the early polychromatic erythrocyte. 



263 A more differentiated cell than figure 262. 



264 A more differentiated cell than figure 263. 



122 



