THE HYPOPHYSIS IN REPTILES 213 



Orru ('00) regarded the hypophysis of Gongylus ocelatus of 

 both ectodermal and entodermal origin. In late stages it con- 

 sists of a dorsal lobe, in contact with the infundibulum, and a 

 ventral lobe completely separated from the infundibulum. 



Staderini has published his observations on reptile hypophysis 

 in various articles. In 1900 he reported (according to Salvi '01) 

 that the hypophysis is connected with the head somites. Later 

 ('03), in a paper on morphogenesis of the hypophysis of Gongylus, 

 he described a primitive single anlage, which, by the develop- 

 ment of two lateral lobes, becomes tri-lobed, and finally four- 

 lobed. The intimate relation of the two isolated lateral lobes 

 to the brain received this author's attention ('05), when the in- 

 fundibulum was described as being divided into three parts at 

 its caudal end. The outlines of the cells of the hypophysis are 

 very indistinct and the round nuclei closely placed. 



Studying the pharyngeal region in Lacerta agilis, Peter ('01) 

 reconstructed this portion, including the hypophysis. A figure 

 of his 'Stage 10,' a 4 mm. embryo of 47 somites, shows a body 

 which is slightly divided into anterior and caudal parts. In the 

 brief descriptions of the characteristics of various stages the 

 author mentioned the appearance of Rathke's pouch in a 3 mm. 

 embryo. 



Salvi's articles ('01, '02, '06) are mainly concerned with the 

 connection between the hypophysis and the premandibular cav- 

 ities in Gongylus, and in attempting to explain the origin of the 

 lateral lobes of the hypophysis. 



Zeleny ('01) studied early stages of the development of the 

 hypophysis in Chelonia and concluded that it is undoubtedly of 

 epiblastic origin. In 7 mm. embryos the hypophysis is a sac- 

 like structure connected to the pharyngeal vault by means of 

 a slender stalk. 



Gemelli ('03) described the early relations of Rathke's and 

 Seessel's pouches in Lacerta agilis and other lizards and also in 

 snakes. In 4 mm. Lacerta embryos the ruptured pharyngeal 

 membrane still clearly separates the two pouches. Later, as 

 the hypophysis increases in size, Seessel's pouch degenerates. 

 Gemelli carefully reviewed the literature and finds that it can 



