190 PEOCEEDIXGS OF THE ACADEMY OF [1888. 



of the scrotum, obtaining in many of the carnivora. As my dis- 

 section of the female generative apparatus of Hycena crocufa that 

 recently died at the Philadelphia Zoological Garden agrees in 

 every respect^ with that of Prof Watson, and as the description of 

 the parts given by that anatomist is excellent, my dwelling further 

 upon the same in detail apart from confirmation, would be super- 

 fluous. I will limit myself therefore, rather to the consideration 

 of how such an extraordinary disposition of generative appara- 

 tus might be brought about and to pointing out its significance in 

 the determination of the homologous parts of the male and female 

 generative organs of the mammalia generally. It is well known 

 that at an extremely eai'ly period of intra-uteriue life, about six 

 weeks, for example, in the case of the human embryo, (Plate XI, 

 fig. 2.) the sex is undistinguishable, ovaries or testicles are undevel- 

 oped, the MuUerian and Wolfiian ducts, bladder and rectum ter- 

 minate in a common receptacle or cloaca, Avhile no external gener- 

 ative organs are observable. As the development of the mammal 

 advances, however, the rectum and bladder separate and open by 

 distinct openings, the anus and urethra, the cloacal condition being 

 retained through life only in Ornithorynchus and Echidna, the 

 Wolfiian ducts become the vasa deferentia, the Mullerian ducts 

 atrophying, supposing the individual to become a male or the 

 Wolffian ducts atrophying and the ^Nlullerian ducts become trans- 

 formed into Fallopian tubes, uterus and vagina, supposing the indi- 

 vidual to become a female, the two bodies up to this moment, indif- 

 ferent functionally, becoming testicles or ovaries respectively — the 

 testicles usually in time descending into a scrotum, the urethra 

 passing through the penis. It is well known that in the female 

 of certain shrews, moles and lemurs and, as recently observed by the 

 author in the South American hare. Capromys pilorides, (Plate XI, 

 fig. 1.) the urethra passes through the clitoris as through the penis 

 in the male of these animals. The fact of the clitoris being traversed 

 by the urethra in the of female Hycena crocuta is, therefore, not such 

 an uncommon condition as at first sight it might appear and confirms 

 the view held by morphologists of the clitoris being the homologue 

 of the penis. Indeed the clitoris only differs from the penis in being 

 smaller and in the fact that the labia minora do not unite under- 

 neath the urethra in the middle line to form what would correspond 



1 It need hardly be mentioned that the contracted kidney and dilated ureter, 

 the latter due to impacted calculi, observable in my dissection, are pathological 

 conditions. 



