Figure 319. — Embryo bone marrow. Composite from two slides. Embryos incubated 11 days 21 hours. 



1,370X. 



2 



3,4 

 5 



6 



9 

 10 



11 



Primordial osteogenic cell in mitosis, late anaphase. 



This cell resembles a metagranuloblast except for 



the Hof. Contains a few small magenta bodies. 



Small mature osteoblasts. 



Large young osteoblast. 



Two small young osteoblasts clumped closely 



together. 



Early mononuclear osteoclast. 



Large mononuclear osteoclast. 



Binuclear osteoclast. 



Multinuclear osteoclast indented by three cells 



of the granulocyte series, 



Multinuclear osteoclast. 



12 



13 



14 



15 



16-18 



19 

 20 



21 



23 



24 



Part of a multinuclear osteoclast showing a ma- 

 genta sphere near the upper edge. 

 Granuloblast indenting an osteoclast. 

 Heterophil promyelocyte. 

 Heterophil metamyelocyte. 



Mature granulocytes. Some show degradation 

 of the rods. 



Early polychromatic embryo erythrocyte. 

 Late polychromatic embryo erythrocyte. 

 Mature embryo erythrocyte of the primary 

 erythrocyte type. 



Mature eriibryo erythrocyte of the later genera- 

 tions type. 

 A pinched-off protoplasmic mass. 



J 42 



