216 E. A. BAUMGARTNER 



To summarize: Gaupp has described a tri-lobed origin of the 

 hypophysis. The majority of other investigators agree that 

 there is a single anlage — Rathke's pouch — from which the hy- 

 pophysis develops. Woerdemann finds an early thickened epi- 

 thelial anlage from which Rathke's pouch grows caudalward 

 and from the anterior end of which the lateral buds and an 

 anterior lobe develop. The majority of investigators also agree 

 that the hypophysis is of ectodermal origin, though Valenti 

 described it as entodermal. Orru believed the origin both ecto- 

 dermal and entodermal, while Hoffman appreciated the diffi- 

 culty of determining from which layer it arises. That the lateral 

 lobes lose connection and become applied to the brain wall is 

 generally conceded for Gongylus. 



Although the terms applied to the various parts of the hy- 

 pophysis during its development have been influenced somewhat 

 by Gaupp's ('93) paper, a table of these terms may help to clear 

 any misunderstanding. 



Anatomy and histology 



Muller ('71) described hypophyseal tubules composed of ir- 

 regular cells surrounded by numerous capillaries in late turtle 

 embryos. 



Stieda ('75) found a small dorsal portion closely united to the 

 lobus infundibuli, and a large ventral lobe, both composed of 

 solid cell cords formed of polyhedral cells with a distinct granu- 

 lar nucleus. The dorsal portion is more vascular and contains 

 pigment cells in turtles. 



Rabl-Ruckhard ('78) in his paper on the central nervous system 

 stated that the hypophysis of alligators is egg-shaped and con- 

 tains no cavity. 



In 1890 Hoffmann referred to the hypophysis in turtles as 

 egg-shaped and closely united with the lobus infundibuli. Stieda's 

 terminology is employed by Hoffmann. 



No direct reference is made by Saint-Remy ('92) to the hy- 

 pophysis of reptiles, though he stated that he had examined 

 lizard and turtle material. He believed that the two kinds of 



