SEASONAL CHANGES IN INTERSTITIAL CELLS 



501 



It is clear from this siuninary that interstitial cell develop- 

 ment does not always run parallel with spermatogenesis. The 

 notable exceptions are the mole (giving precedence to the most 

 complete report by Tandler and Grosz) and the woodchuck. 

 In the latter case the interstitial cells suddenly undergo retro- 



Curves of Seasonal Dimorphism of Testis 



- 5permato^ene5i5 



ANIMAL M.m 



= Interstitial Cells ; IB-^l - hibernation 



THE AMERICAN JOURNAL OF ANATOMY, VOL. 22, NO. 3 



