The Urogenital Organs 195 



them, on the side towards the upper wall of the 

 cloaca, a fairly deep furrow that extends to the tip. 

 According to Rathke these shafts are not of cavern- 

 ous tissue, but the tube is lined by a layer of this 

 tissue. 



The glans, e, consists of two parts between 

 which, where they leave the shaft of the penis, is 

 a funnel-shaped hole, wider towards the free end 

 of the penis and divided into similar lateral halves 

 by a fold of skin. The glans is much shorter than 

 the shaft of the penis. The covering of the penis 

 is much thinner than the mucous membrane of 

 the cloaca and is thinnest along the groove; it 

 extends from the shaft over the glans without 

 forming a foreskin. 



The base of the penis is attached to the pubis 

 near its symphysis. With this base the most 

 anterior part of the strong ring-muscle of the 

 cloaca is closely attached by a fairly large mass of 

 fibrous tissue. Rathke fails to find any muscles 

 that are concerned alone with the copulatory 

 organs. 



In the copulation of the crocodile, according to 

 Rathke, the penis is erected, though how this is 

 caused is difficult to say since the corpora cavernosa 

 consist only of fibrous tissue and the cavernous 

 tissue lining the groove is very thin. The penis 

 can, therefore, project only a short distance from 

 the cloaca. The cavernous tissue is capable of 

 causing only a slight elongation of the shaft, but 



