1002 



Jill. C. F. SONNTAG OJf THE TKLYIG MUSCLKS 



muscles. The corpus spongiosum has a small bulb attached to 

 the triangular ligament. Its diameter is greater tluui that of 

 either corpus cavernosum. The corpora cavernosa soon come 

 together. At first they are separated by a thick septum formed 

 from their contiguous walls, but the septum soon thins out and 

 disappears. The dorsum has a groove for vessels anil nerves, but 

 the corpus spongiosum is not lodged in a ventral groove. These 

 conditions are seen in text-fig. 58 E-H. In the Orang the 

 conditions are very similar to the above for the septum between 

 the corpora cuvernosa soon disappears ; and the core of ei'ectile 

 tissue is smaller and the fibrous tunic is relatively thicker than in 

 the Chimpanzee and Man. 



The penis contains a small bone, first described by Crisp *. It 



Text-ficrui^e 58. 



*- f- " ■ 



Cross- sect ions through the prostate and urethra (A-C) and through the cloinonts of 

 the ijcnis (E-II). Tlicso sections arc arranged in order from the base of the 

 ])rostiite to the aiitcfior part of the penis ; D : the orilices of the cjaeiilatory 



jlii/ii-u in flu. iii'nMirn 



ducts in tlie urethra. 



is a little more than half an inch long, fusiform in shape, witli 

 rounded extremities. Crisp figures a rather different shape, 

 whilst Milne-Edwards (6) described and figured the bone as ex- 

 panded towards one end in the Orang. The penis is fixed to the 

 front of the pubis by two suspensory ligaments, between which 

 vessels and nerves run to the dorsum. 



The scrohmn is capacious, and varies in size from time to time. 

 The skin is darkly pigmented, and has crisp hairs. The median 

 raphe is marked on the surface as a white line, which runs on to 

 the ])enis. The Gibbon has not got a prominent scrotum, no 

 raiiho is present, and the root of the penis lies nearly between the 

 ischial callosities. 



'\l\\(i perineum is long in the male, but sliort in the female. 



* Proc. Zool. Soc. 1805, p. 18. 



