EXTERNAL ORGANS OF GENERATION. 287 



margins of the fimbriae, the ciliated epithelium is continuous 

 with the epithelium of the peritoneum, presenting the excep- 

 tional example of an opening of a mucous-lined tube into the 

 cavity of the peritoneum. The membrane of the tubes has 

 no mucous glands. 



It is not necessary to enter into a minute description of 

 the external organs of the female. Opening by the vulva, 

 externally, and terminating at the neck of the uterus, is a 

 membranous tube, the vagina. This lies between the bladder 

 and the rectum ; it is curved, being about four inches long in 

 front, and five or six inches long posteriorly. There is a con- 

 stricted portion at the outer opening, where we have a muscle, 

 called the sphincter vaginae, and the tube is somewhat nar- 

 rowed at its upper end, where it embraces the cervix uteri. 

 The inner surface presents a mucous membrane, marked by 

 transverse rugae, with papillae and mucous glands. Its sur- 

 face is covered with flattened epithelium. The vagina is 

 quite extensible, as it must be during parturition, to allow 

 the passage of the child. It presents a proper coat of dense 

 fibrous tissue, with longitudinal and circular muscular fibres 

 of the non-striated variety. We have, also, surrounding it, 

 a rather loose erectile tissue, which is most prominent at its 

 lower portion. 



The parts composing the external organs are abundantly 

 supplied with vessels and nerves. In the clitoris, which cor- 

 responds to the penis of the male, and on either side of the 

 vestibule, we find a true erectile tissue. 



149 



