Fig. 5. Section of normal pig testicle in active spermatogenesis. The droplets of 

 neutral fat lying in the Sertoli cells form an outline of the seminal tubule. Numerous 

 small droplets of fatty material are seen toward the lumen. Altmann's fixation (osmic 

 acid and potassium dichromate) ; stained with Bensley's neutral gentian. (Hanes and 

 Rosenbloom, 1911, Plate xxxvii, Fig. I.) 



Fig. 6. Section of cryptorchid pig testis, stained with Sedan III and hematoxylin. 

 The tubules are much smaller than in the normal testicle and are lined only by a 

 layer of Sertoli cells which contain a large number of neutral fat droplets. No sperm 

 forming cells are present. The Leydig (interstitial) cells are seen, on comparison with 

 Figure 5, to be greatly increased in number. 



Figures 5 and 6 are microphotographs taken under exactly the same magnification. 



445 



