GROWTH AND STRUCTURE OF HYPOPHYSIS IN RAT 



339 



TABLE 4 



Average diameter of nuclei of parenchyma cells in the hypophysis of the albino rat 

 under various conditions. Direct measurements by means of the filar microme- 

 ter. Average {and range) of 100 nuclei in each case 



1 Including some eosinophiles. 



philes. During inanition they show in most cases less shrinkage 

 than do the pars anterior nuclei (especially of eosinophiles), 

 though here as elsewhere much individual variation is found. 



OCCURRENCE OF MITOSIS IN THE PARTS (LOBES) 



In order to determine the rate of mitosis in the hypophysis of 

 the rat under various conditions, the number of mitoses was 

 counted in 40 cases, as shown in table 5. In each case, one or 

 more (up to 5) entire coronal (frontal) sections, chosen to show 

 maximmn areas (especially of partes intermedia and anterior) 

 were systematically examined by means of a mechanical stage, 

 and the total nmnber of mitoses counted for each part (lobe). 

 As might be expected, much individual variation is found, both 

 in different individuals and in different sections of the same 

 gland. The general trend, however, is clear and is well shown 

 in the condensed table of averages (table 6). Amitosis was not 

 observed in anv case. 



