HYPOPHYSIS AFTER CASTRATION 451 



Two months after castration {98 days old) 



At two months after castration (fig. 4) the differences already- 

 noted between normal and experimented hypophysis are in- 

 creasingly apparent, and these affect all thi-ee types of cells. 

 The basophiles are now the most conspicuous elements in the 

 experimented hypophysis and in some of them vacuoles have 

 appeared. These vacuoles are filled with a homogeneous secre- 

 tion which stains like the colloid in the pouch of Rathke, and 

 probably from these cells come the abundance of colloid, which 

 is now seen in the lumen of the pouch of Rathke. There are two 

 sizes of population recognizable among the basophiles, with, 

 however, many of intermediate size. In general, those which 

 have the vacuoles are the larger, but here and there is seen a cell 

 without a vacuole, as large as those possessing it. The 

 smaller basophiles have usually a more homogeneous cytoplasm 

 and are again regarded as immature basophiles. The cells 

 with vacuoles are still greatly in the minority. Some baso- 

 philes are more coarsely granular than others, and this seems to 

 depend upon the age of the cell; i.e., the time which has elapsed 

 since differentiation. Sometimes a cell is seen with many 

 minute vacuoles (1 to 2 n) in one hmited area. This probably 

 represents a first stage towards the development of one or more 

 large vacuoles. 



Measurements of those with vacuoles show a mean size of 

 19.2 /iX 15.9 ju, while those wthout vacuoles measure 14.7 /xx 12.9 m. 

 The larger cells have slightly larger nuclei 6.7 /x x 5.6 ^ as com- 

 pared with 5.9 ju x 5.5 ^ for the smaller. The vacuoles of the 

 largest cells average 10.8 m x 7.4 /x. 



The acidophiles and the reserve cells of the experimented 

 hypophysis are not so conspicuous as in the normal. Often 

 when measuring acidophiles, there appear to be two sizes of 

 population. Those seen along the margins of blood-streams 

 have more cytoplasm, than those which are found in the cell- 

 masses away from the blood vessels. It seems that this apparent 

 difference may be, however, only a result of the cells having been 

 cut in different planes. Measurements of the acidophiles show 

 them to be not as large, on the average, in the experimented 



