PLATE 1 



Fig. 1. Microphotograph x 213. Tubal ovum of an infantile rat treated with 

 prolan. Five segments of the ovum with granulosa cells adhering to them. 



Fig. 2. Microphotograph X 473. Five segments of an ovum in the follicle of an 

 infantile hypophysectomized rat. Cell no. 1 contains a nucleus, cell no. 2 has a 

 nuclear spindle, cell no. 3 has the shadow of a nucleus, cell no. 4 is without 

 nucleus, cell no. 5 is cytolytic. 



Fig. 3. Drawing x 790. Three segments of an ovum in the follicle of an in- 

 fantile hypophysectomized rat. Two of the segments contain nuclear spindles, 

 the third a polyaster. 



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