CHAP. IV] THE GENERAL ANATOMY OF GORILLA 209 



with the age of the animal, whereas it decreases with age in Man. 

 For the position of the caecum cf. Figs. 140 and 141. 



The pancreas does not differ apparently from that of Man : the 

 characters of the spleen however are distinctive, the most striking 

 being the extreme attenuation of this organ in its lower parts, 

 so that its extremity is tapering and caudiform, suggesting the 

 conditions obtaining in the lower Anthropoidea and in the Lemurs. 



The liver of the Gorilla (cf. Fig. 142 ; the inferior aspect of 

 the liver of a young Gorilla is represented) differs from those of 

 the other large anthropoids and of Man in the more marked 

 tendency to subdivision of right and left lobes, a character which 

 assigns a comparatively lowly place to the Gorilla in a comparison 

 of the higher Primates based on the anatomy of the liver. 



The general relations of the peritoneum are the same as those 

 of Man. 



K. Genito-urinary System. The genito-urinary system 

 offers no important differences from that of Man. 



The kidneys may present but a single pyramid as in Hylobates, 

 but this is a variable character in Gorilla. The genitalia of the 

 female differ in arrangement from the human type, inasmuch as 

 the vulva is directed posteriorly. The vagina, uterus, Fallopian 

 tubes, and ovaries resemble the human organs. The existence of 

 a hymen is denied by various observers : this membrane would 

 thus appear to characterize the Hominidae alone among the 

 Primates. 



In the male, the glans penis is smaller relatively and absolutely 

 than that of Man, but is nevertheless more distinct and relatively 

 larger than in other Simiidae. There is an os penis, as in the 

 lower Primates, and other Eutherian mammals. The Hominidae 

 alone amongst Primates would seem to be characterized by its 

 absence. 



In an adult male Gorilla I found the tunica vaginalis of 

 the left testis completely free from all connection with a 

 processus vaginalis. The cavity of the tunica vaginalis was 

 distinctly smaller than in Man and in the Chimpanzee. A pedun- 

 culated hydatid was present. The testis measured 51 mm. in 

 its longvr axis. In an adult male Chimpanzee, the right testis 



d. m. 14 



