102 ORGANS OF GENERATION. 



but one: in that case its origin will be reversed, and commence 

 in the middle line of the perineum instead of terminating there. 

 As this muscle, and the erector penis, touch by their conti- 

 guous faces, it is difficult to get into the membranous part of 

 the urethra in lithotomy without cutting through the muscular 

 fibres of one or the other. 



It propels the urine and semen forward. 



, 



The Musculus Transversus Peritiet, 



As its name implies, passes directly across the perineum ; ife 

 arises from the inner side of the ischium, just at the origin of 

 the erector penis, and is inserted where the sphincter ani and ac- 

 celeratores urinae join. 



I have observed that when the lower part of the accelerator 

 was extended much below its usual line, and strongly deve* 

 loped, that the transversus was very irregular in its origin and 

 course ; consisting frequently of a few fibres which did not de- 

 serve the name of a distinct muscle, and lying almost unappro- 

 priated in the adipose matter of the part. v 



Occasionally, a fasciculus of muscular fibres exists, called, by 

 Albums* Transversus Perinei Alter, which arises in front of the 

 transversus: it seems generally to be a loose fasciculus of the 

 accelerator urinae muscle, and is inserted into the perineal junc- 

 tion just behind it. 



The use of these muscles seems to be to contribute to fix the 

 bulb of the urethra. 



The Musculus Sphincter Jlni, 



Consists in a plane an inch thick, of elliptical fibres imme- 

 diately beneath the skin of the anus, and which surrounds the- 

 latter in order to keep it closed,. The long diameter of the el- 

 l.ipsis is extended from the coccyx towards the symphysis pubis,. 

 and has its angles very much elongated ; the anterior may be 

 traced terminating insensibly in the posterior face of ihe scro- 

 tum. It has two fixed points, the last bone of the os coccygis 

 behind, and perineal union of the other muscles in front ; its la^ 

 teral diameter occupies about one- half of the space betvveen the 

 tuberosities of the ischia, and. it is in the middle of this spa.ce.. 



