450 CHARLES R. STOCKARD AND E. M. VICARI 



the one just described (fig. 1, pi. 87). Longitudinal sections 

 from three other dachshund pituitary glands are shown in 

 plate 87. None of these is exactly through the sagittal plane, 

 as is figure 1, and on this account they fail to present entirely 

 similar outlines. Nevertheless, so far as the dog pituitary is 

 concerned, the several parts of the three glands can be very 

 readily examined in these sections. In all three, the residual 

 lumen of Rathke's pouch is clearly open between the pars 

 distalis and pars intermedia, and diverticula lead away from 

 it in the pars tuberalis region to form slender spaces ex- 

 tending among the glandular tissues. These are very extensive 

 in figure 4. The pars intermedia intimately penetrates the 

 nervosa to varying extents in these photomicrographs, and 

 small colloidal follicles may be detected along this transitional 

 zone. 



The general distribution of acidophile and basophile, or 

 alpha and beta cells in the pars anterior is not possible to 

 estimate from examination of these low power photomicro- 

 graphs which are primarily intended to give the histologic 

 topography of the gland. However, the acidophiles are usu- 

 ally stained red, and their cytoplasm produces a darker shade 

 in the photographs taken at higher magnifications. The two 

 chromophilic types are distributed in the usual manner, and 

 many countings indicate that they exist within the range of 

 normal proportions. Rasmussen ( '38) finds that in the human 

 pituitary the acidophiles generally tend to concentrate in 

 large areas posteriorly in each lateral half of the pars distalis, 

 and therefore in anterior and marginal zones, as well as near 

 the mid-sagittal plane, these cells are less numerous. Such 

 areas are comparatively richer in chromophobes and baso- 

 philes. These general arrangements also apply to the dis- 

 tribution of the chromophilic types in the dog pituitary. 

 Rasmussen 's extensive counts of pituitary cells from male 

 and female human beings ('29, '33, '38) show that the acido- 

 philes constitute from about 20 to 60 per cent of the total cell 

 number, while basophiles exist in much more variable and 



