THE FEMALE ORGANS OF GENERATION. 247 



is termed the prostatic part of the urethra ; after leaving the 

 prostates, till it reaches the corpus spungiosum and caver- 

 nosum, it is known as the membranous portion of the 

 urethra ; all the remaining part being called the muscular 

 urethra. The reason of this last name is, because under 

 this last division of the duct runs a well-marked muscle, 

 attached to the corpus cavernosum upon either side, and 

 passing beneath, and in close connexion with, the urethra. 

 The name of this muscle is the " accelerator urin<^ ;" its use 

 being to speed the passage of any fluid through the duct. 

 The most posterior parts of the corpus cavernosum are 

 spoken of as its crura, to which, proceeding from the lower 

 surface of the points of the ischium, come two muscles to be 

 inserted, called the erectores, and their purpose is obvious, 

 being implied in their name. The urethra, underneath the 

 crura, is sometimes termed the bulbous portion, because in 

 this particular place it is largest. 



The urethra throughout its course is highly sensitive and 

 vascular. It is a mucous membrane, and by its plentiful 

 secretion is protected from the effects of the urine ; along 

 its course are several slight prominences, which lead to small 

 mucous glands ; these prominences are called lacunae, being 

 the mouths to ducts. The external orifice of the urethra 

 is known as the meatus urinarius. The arteries of the penis 

 spring chiefly from the pudic, the artery of bulb, and the 

 pudendal ; the veins seem to have no settled name. The 

 nerves arise from the lumbar, and from the sacral plexuses. 



THE FEMALE ORGANS OF GENERATION. 



The perceptible parts of generation in the mare consist of 

 the labia majora or labia ; the labia minora or vulva : the 

 clitoris and the meatus urinarius, to which some add the 

 beginning of the vagina ; but as we prefer to describe parts 

 as a whole, we omit the last structure. 



The genital opening of the mare is surrounded by two full 

 folds of projecting substance, without hairs, but covered by 

 a dark coloured skin. These are the labia, or labia majora, 

 and they are principally composed of fat and loose cellular 

 tissue ; within these are situated another fold, but of a 

 much more moist and vascular appearance. The last are 

 the labia minora, or vulva, and are much thinner and more 



R 4 -*- 



