R. H. Whitehead 



195 



in the granule-bearing cells of the embryonic gland are smaller and not 

 so limited to the periphery of the cells. 



In preparations stained with Sudan III or osmic acid numerous 

 globules of fat, oftentimes very large, are found constantly in the 

 seminal tubules; but the interstitial cells contain at the most only a 

 few fine droplets — many of them contain no fat whatever. 



The collections of cells have a rich blood-supply through a network 

 of thin-walled capillaries. A rather striking feature in the testis at 

 this age is the large number of eosinophile leucocytes, both in capillaries 

 and free among the interstitial cells. 



In the pig two months old Leydig's cells, in general, are smaller than 

 in the preceding specimen. The varieties of cells described above are 

 still present, but with some differences. 



Fig. 3. Fig. 4. 



Fig. 3. A small area of testis in pig one month old. x 50. 

 Fig. 4. Small area of testis in pig five months old. x 50. 



The granule-bearing cells are scanty, while the cells with pale periph- 

 ery are quite abundant, as are also the vacuolated cells, the two to- 

 gether forming the great majority of the interstitial cells. In the case 

 of the vacuolated cells the number of inclusions is noticeable. In many 

 of these cells the septa between the vacuoles are breaking down. 



At three months the convoluting of the seminal tubules has increased 

 considerably, so that many more cross-sections of them are seen, and 

 the interstitial cells are divided up into smaller collections. The break- 

 ing down of the septa between vacuoles and the concentration of cyto- 

 plasm around the nucleus have also progressed, so that now the indi- 

 vidual cells are much smaller than in the preceding stages, and most 

 of them present the pale periphery (Fig. 2). A very few containing 

 acidophile granules may be seen. 



