210 RODENTIA. 



the abdomen, and much in the same place as the Fallopian tubes in the 

 female. They are very thin in their coats, and are honeycombed in 

 their inside. They open by very large ducts into the urethra at the 

 common place. On their under surface, just before they enter the 

 urethra, they receive the ducts of the prostate ; at the place where they 

 open there is a large opening common to both, which is hard and 

 irregular round its edge. This common opening is as short as you can 

 conceive, and in the angle of union of the two openings are the two 

 orifices of the vasa deferentia, but they do not communicate. The 

 vesiculae contain a gelatinous substance somewhat granulated, which 

 becomes thicker and thicker towards their openings : the same kind is 

 to be observed in the prostate, which seems to be no more than convolu- 

 tions of ducts, very like the caeca at the pylorus in some fishes. 



This fluid is continued into the urethra, and extends through its 

 whole length, becoming thicker and thicker, so that it is a very hard 

 substance in the urethra, but is here of a whiter colour ; perhaps being 

 mixed with some semen. 



The penis is bent back, in the flaccid state, close to the anus, so that 

 they are retromingent ; it is hid entirely within the skin, so that the 

 prepuce is pretty long. There is a bone in the anterior part of the 

 penis, which is about half an inch long, and a small bone on each side 

 just under the skin, like two splints. Two muscles that arise from the 

 pubis form tendons which pass along the convex side of the penis and can 

 extend it, when it is bent. The membranous part of the urethra is 

 muscular, as usual. There is a gland [Cowperian] on each side of anus 

 as in the squirrel, rat, &c, which sends a duct extending to and entering 

 the urethra, as in the rat. Bound the verge of the anus are many 

 sebaceous glands, and that part of the skin can be taken in so as to 

 appear to be the anus itself l , till it is again inverted. 



The lips are a little peculiar. The contents of the thorax are as in 

 a dog. 



Supposing I have called the foregoing bags ' vesiculae seminales,' yet 

 I do not believe that they are so for these reasons : — first, the mucus 

 that they contain is by much too thick : secondly, it is thickest at the 

 entrance of the ducts, where we would expect to find it thinnest if it 

 were semen ; for it would be natural to suppose that the last that came 

 in would be the thinnest : thirdly, it is not natural to suppose that it 

 would be in such quantity as to lie in the urethra : fourthly, it is not 

 at all of the colour of the semen that is in the vasa deferentia, except- 

 ing that part that is in the urethra which seems to be mixed with it : 



1 [Home, Comp. Anat. i. p. 449.] 



