MASS. EXPERIMENT STATION BULLETIN 331 



Photomicrographs of Sections of the Testes at Various Ages during Development. (130x) 



The Ram 

 Figure 1 — 42 days 

 Figure 2 — 126 days 

 Figure .? 147 days 

 Figure 4 — 168 days 



The Bull 

 Figure 5 — 63 days 

 Figure 6 — 224 days 

 Figure 7 — 261 days 

 Figure 8 — 450 days 



