452 CHARLES If. STOCKARD AND E. M. YICARI 



smaller proportions, composing from 5 to 27 per cent of the cell 

 mass. The less differentiated neutrophiles or chromophobes 

 make up from 34 to 66 per cent of all cells. We may express 

 these estimates in other words and state that the percentage of 

 acidophiles in man may range from four to twelve times 

 higher than the low limit of basophile percentages, and that 

 they range from only equal value to about double as high 

 as the basophile upper limit. There is only slight intimation 

 that the low percentage of acidophiles is necessarily accom- 

 panied by a rise in percentage of basophiles; the variations 

 in relative percentages seem to be largely independent. 



In the dog pituitary, the proportion of beta cells, or baso- 

 philes, to acidophiles is in general somewhat lower than the 

 relative percentages given by Rasmussen for the human. We 

 are indebted to Doctor S. R. Magruder for his assistance in 

 making the counts of chromophilic types for the dog pituitaries 

 over a period of 2 years. The method employed for counting 

 the cells w r as as follows : The anterior pituitary lying ventral 

 to the pars nervosa is conveniently divided into anterior, 

 median and posterior thirds. Each of these thirds was then 

 subdivided into zones A, B and C being, respectively, median, 

 or adjacent to the residual lumen, intermediate and peripheral. 

 A band of definite microscopic width passing through the 

 three zones in the posterior ventral region was mapped, and 

 the acidophiles and basophiles within each zone of this band 

 counted and recorded. The same procedure was then followed 

 for the medio-ventral and anterior ventral thirds of the pars 

 distalis. This method of counting gives the relative distribu- 

 tion of acidophiles to basophiles from the posterior to the 

 anterior end of the gland and from the zone adjacent to the 

 pars intermedia to the periphery. The cells in from three to 

 six longitudinal sections at various distances from the sagittal 

 plane were counted for each pituitary, and the averages of 

 these counts were used in estimating the relative proportion 

 of one cell type to the other. The counts were made under 

 high magnification only, and with the stains employed, hema- 



