THE (iKNEllATIVK OHOANS IN THE JIALE CIIIMPANZi:i:. 1001 



48. Oil the Pelvic Muscles and Geiierutive Organs in the 

 Miile Chini|)an/,ec, By (.*f[AiiLEH F. tSoNNTAf), M.D., 

 b'.Z.S., Anatoniisb to the Society and Denioustra'tor of 

 Anatomy, University College. 



[Rccnivcd October 1, 1923 : Read November G, 1923.] 



(Text-figures 58-64.) 



The present paper is intended to fill a gap in the literature on 

 the anatomy of the Chimpanzee, for, although there are descrip- 

 tions of parts of the male generative organs and the arrangement 

 of the muscles and pelvic viscera, no full account of these parts 

 exists. Tliey liavo been described fully in the female by Lart- 

 schneider (4) juid myself (9). The matei-ial on wln'ch this account 

 is based consisted of the pelvis of an adult male animal, which 

 lived in the Society's Gardens for nine years, and a young male, 

 about nine years old, which I received soon after it arrived in 

 London. 



The Male Generative Organs. 



Keith (2) states that " The external generative organs are of 

 surprisingly small development ; but it must be kept in mind 

 that they have been studied on animals, for the greater part 

 immature, or, if adult, upon animals contracted by long immer- 

 sion in alcohol." In the two fresh specimens examined by me 

 the penis was certainly small, but the scrotum with its contained 

 testicles was large. 



The 2^6nis is tapering, and it is frequently seen in the erect or 

 semi-erect condition. Duvernoy (1) points out that it is often 

 erected when the animal is drinking, particularly if a little wine 

 is added to the fluid. x\ftor death the penis may bo quite con- 

 cealed by the prepuce. The anterior extremity has a slight 

 collar-like rim, with a small process underneath. This is the 

 sole representative of the glans penis. In the Orang, according 

 to Milne-Edwards (6), there is no rim ; and Duvernoy figures an 

 expanded, vertically cleft glans of dark colour in the Gorilla. 

 Kohlbriigge (3) figures a globular expansion of the end of the 

 penis in the Gibbons. I also observed a well-marked glans 

 penis. The meatus urinarius is vertical and there is a fossa 

 navicularis. The prepuce is thick in both Chimpanzees and 

 Gibbons. 



Tlie corpora cavernosa are cylindrical and of small, but vmiforiii 

 diameter. ' They are not expanded close to their origins as in 

 Man. Tliey are bound down to the lov/er borders of the pubic 

 rami, and are covered on three sides by the ischio-cavernosus 



