MAMMARY GLANDS. 363 



MUSCLES OF THE FEMALE GENITAL SYSTEM. 



Erectores clitoridis. — A pair of very small muscles analogous 

 to the erectores penis of the male. They arise from the ischial 

 arch, and are attached to and closely associated with the crura of 

 the clitoris. 



Constrictor vulvce anterior. — This is considered the homo- 

 logue of Wilson's muscle ; its fibres are arciform, and embrace 

 the posterior part of the vagina, below and at the sides, its 

 aponeurosis being reflected on the sides of the rectum. 



Constrictor vulvce posterior. — Included in the labia of the 

 vulva, and disposed as a sphincter, this muscle is attached to the 

 skin by cellular tissue. It is attached to the sphincter ani above, 

 and also to the sacrum by the suspensory ligaments. It is the 

 analogue of the sphincter vaginae in the human subject. 



Suspensory ligaments. — Attached to the sacrum above, and 

 uniting under the rectum, these structures resemble the retractor 

 penis of the male. They again separate and become lost laterally 

 in the posterior constrictor muscle. 



From the above descriptions it will be apparent that in the 

 male animal the female generative organs are indicated, as are 

 the male organs in the female. Thus in the male the sinus 

 pocularis represents an undeveloped uterus ; and in the female 

 the clitoris a rudimentary penis. This points to the fact that in 

 early foetal life there is no distinction of sex, each animal having 

 rudimentary male and female generative organs ; only one of 

 these becomes developed, thus determining the sex of the animal. 

 Should both systems of organs in the same animal become more 

 or less developed, but neither of them perfectly so, the animal is 

 said to be heo^maphrodite, 



MAMMARY GLANDS. 



The mammae, or mammary glands, are characteristic of the 

 highest class of the animal kingdom — the mammalia. They are 

 compound racemose glands, which secrete milk for the nourish- 

 ment of the recently-born animal. In the young female, as in 

 the male, they are rudimentary, becoming developed in the 

 former at puberty, or when the female is fit for reproduction. 

 During utero-gestation they gradually enlarge, and at parturi- 



