264 E. A. BAUMGARTNER 



and a part covering the body of the posterior lobe. He described 

 acini lined by clear cells and containing colloid in the former. 

 More recently Tilney ('13) has given an excellent description of 

 the pars tuberalis in mammals and birds. In the cat it is vas- 

 cular and has an acinar arrangement of small, basophilic cells, 

 sometimes ■ granular, with either large or pycnotic nuclei. In 

 the adult fowl, the cells grouped in masses are faintly or deeply- 

 staining basophiles. In the pig, Miller ('16) described a corti- 

 cal zone of chromophobic cells around the anterior lobe. There 

 seems, then, to be a complete homology of these parts in the 

 forms described. 



In accordance with Tilney' s conclusions from the cat and fowl, 

 histologically there are three distinct parts of the adult epithelial 

 hypophysis in turtles and alligators, but only two in snakes and 

 some lizards (Sceloporus). 



Lothringer ('86) stated that hypophyseal cysts, lined by a 

 ciliated epithelium, are present in rabbits. Other investigators — 

 Peremeschko ('67) and Thaon ('07) (according to Stendell) — 

 have described a ciliated epithelium bordering the residual lumen 

 of the hypophysis. Stendell is inclined to doubt the correct- 

 ness of these observations in mammals. The presence of ciliated 

 cells in the hypophysis of the higher vertebrates is difficult to 

 explain. 



Secretions 



Tubules, containing a homogeneous substance or a reticular 

 .meshwork in their lumina are found in the anterior lobe of the 

 hypophysis of turtles, occasionally in lizards, and in the anterior 

 lobe proper, as well as in the band encircling it, in alligators. 

 This is evidence of a secretion being emptied into these spaces. 

 In turtles both the central and proximal ends of some of the 

 cells are granular and darkly staining. In alligators usually 

 only the peripheral part is granular. 



In the peripheral zone of the pars intermedia of the large alli- 

 gator, round homogeneously-staining masses are present. These 

 may be as small as the nucleoli or larger than the nuclei, and 

 are found in groups or as single masses. Such masses occa- 



