THE STRUCTURE OF FREE-MARTIN GONADS 



83 



rearrangement of these cells, as the comparatively large nuclei 

 tend to be crowded into a single layer at the periphery. This 

 leaves an area of the syncytium more or less free of nuclei in 

 the center of the cord, but no lumen is formed. Examination of 

 older embryonic ovaries shows similar conditions. This is the 



S 







Fig. 7 Portion of a transverse section through the testis of a mature male 

 foetus (89 cm.), Bos 3. bv, blood-vessel; gc, primordial germ cell; s, seminiferous 

 tubule showing nuclei of the supporting epithelial syncytium arranged into a 

 single layer at the periphery; strands of cytoplasm extending from the inner 

 ends of the oval nuclei toward the center of the tubule; st, tubulus rectus (straight 

 tubule) in conjunction with a seminiferous tubule; i, inter-tubular tissue. 

 X 307. 



normal limit of differentiation, as they are destined to degener- 

 ate; no medullary cords are evident in ovaries from birth on. 

 In the youngest normal testis examined (4.8 cm., N 13) the 

 sexual cords are unorganized, as the walls can only be distin- 

 guished with difficulty and the supporting epithelial cells are 



