ARREST OF DEVELOPMENT. 97 



in which the penis is contained in a sheath the abdominal in- 

 tegument is united to the penis along the edges of this groove, 

 and the usual retractor muscles are absent. In the most 

 marked forms the scrotum is completely divided into two lateral 

 organs, which in the human subject exactly simulate the -labia 

 of the female. The urethra opens at the base of the penis 

 between the lateral halves of the scrotum. 



In Androgyny the penis is very rudimentary or absent, and 

 the scrotum is cleft. The urethra and sexual orifice are distinct 

 in the human subject ; but in animals this is not usually the 

 case. The sinus pocularis, or male homologue of the uterus, is 

 largely developed and generally has two more or less developed 

 cornua. The vasa deferentia are commonly impervious through- 

 out a considerable portion of their length. The testes ara 

 abdominal or lie in the inguinal canal ; they are usually much 

 atrophied, and probably never exhibit their normal structure. 

 The subjects of this malformation so closely resemble the female 

 externally that it is impossible to determine the sex without 

 dissection. Many forms of gynandrous females resemble normal 

 males far more closely than even slightly androgynous males do. 



In most animals the penis is present, but permanently re- 

 tracted in lateral sigmoid curves, and remains very diminutive ; 

 it is usually entirely concealed in a fold of integument, and 

 strongly resembles a clitoris. In Bulls, where the bulb of the 

 urethra is normally a capacious pouch, it forms the termina- 

 tion of the urino-generative tract, and closely resembles the 

 vagina of the female. Such animals are called " Free Martins " 

 when, as is usually the case, they are twins with perfect males ; 

 they frequently have well-developed teats and much larger mam- 

 mary glands than are normal in the male. The urethral bulb 

 terminates in a solid sexual cord of enormous dimensions ; this 

 cord is always surmounted by a pair of cornua ; sometimes it 

 is perforated by the Miillerian ducts, which run through its 

 entire length and terminate blindly in the cornua. It will be 

 remembered that the Miillerian ducts normally disappear in 

 the male at an early period, but that they persist in the female 

 and form the uterus and Fallopian tubes. This structure is 

 therefore the homologue of the female uterus largely developed. 



