198 HAROLD J. COOPER 



the basal end of the cell may be still quite filled with its acido- 

 philic matter, while in other cells the whole cytoplasm is free from 

 granulation and reduced to. a pale meshwork, simulating charac- 

 teristic chromophobic cells (figure 116). The chromophobe cells 

 seem, then, to represent those cells which have given up their 

 secretion, which has probably diffused through the endothelium 

 into the sinus. The intermediary granular cells present no 

 marked irregularities. The failure of observers to definitely trace 

 the secretion into the blood channels does not seem to me to 

 discredit this conception, which is held by not a few investigators. 



The connective-tissue framework of this lobe is taken up by 

 Dostoiewsky ('86) in detail, and in the ground-squirrel there are 

 no particular variations from his description. The peripheral 

 bundles derived from the dural capsule are the thickest and form 

 beams which divide and subdivide, until, when they reach the 

 central regions of the gland, they consist of very slender fibers 

 forming a recticulum which encloses small groups of cells. It is 

 against these fibers that the cells rest, and by them and by the 

 sinusoids the groups of cells are outlined. 



2. pars juxtaneuralis. a) Pars infundibularis. The degree to 

 which the pars neuralis is enclosed by the pars infundibularis 

 varies according to the species. In the ground-squirrel the pars 

 infundibularis is concave on the neural side, and, being somewhat 

 cup-shaped, it extends over the pars neuralis peripherally. This 

 envelopment is by no means complete, but at least half of the 

 neural portion is so enclosed (compare figs. 1 and 2). 



The basophilic character of the cells of this lobe has been indi- 

 cated earlier in this paper, and in no cases did they show any 

 acidophilic granulations. They are considerably smaller as a 

 rule, 4/x to 7/x in diameter, but occasionally large giant-like cells 

 are observed, which, if they are pale, look like colloid cysts. The 

 nuclei are correspondingly smaller in the typical cells, but their 

 nuclear characteristics are about the same. Bordering on the 

 lumen, there are cells making up the free margin (border cells) 

 which send processes in among the glandular ones. In the pars 

 infundibular these processes are better seen than in the distal 

 lobe for the reason that the large cysts and an occasionally large 



