336 PERINEAL MUSCLES. 



skin is capable of being corrugated and relaxed in a greater 

 degree than the skin in other places. 



The muscle proper to each testicle is the 



Cremaster. 



Arises from the internal oblique, where a few fibres of that 

 muscle intermix with the tran^versalis, near the juncture of the 

 os ilium and pubis, over which part it passes, after having 

 pierced the ring of the externus obliquus ; and then it descends 

 upon the spermatic chord. 



Inserted into the tunica vaginalis of the testicle, upon which 

 it spreads, and is insensibly lost.* 



Use. To suspend and draw up the testicle, and to compress 

 it in the act of coition. 



The penis has three pairs of muscles : 



1. Erector Penis. 



Arises, tendinous and fleshy, from the tuberosity of the os 

 ischium, and runs upwards, embracing the whole crus of the 

 penis 



Inserted into the strong tendinous membrane that covers the 

 corpus cavernosum penis, nearly as far as the union of these 

 bodies. 



Use. To compress the crura penis, by which the blood is 

 pushed from it into the forepart of the corpora cavernosa ; and 



* M. J. Cloquet says, that the scattered fasciculi of this muscle are collected 

 after their distribution on the tuniea vaginalis, and run up on the inner side of 

 the chord, to be inserted into the spine of the pubis. He makes the inference 

 from this, that the cremaster is a kind of muscular loop, drawn down by the 

 descent of the testicle. I am satisfied that the muscle in robust subjects, fre- 

 quently exists, more or less, after the manner in which he speaks of it : but, in 

 the emaciated, it is very indistinct, as regards such an insertion. In the cases 

 where I have seen this insertion into the spine of the pubis, the quantity of 

 muscular fibre has been by no means so great there as at its origin. This ob- 

 servation of M. Cloquet's is ingenious and interesting, but it is well worthy of 

 consideration, that Mr. John Hunter's opinion, in his paper on the descent of 

 the testicle, is opposed to it, and on the following grounds : in the young ram, 

 and in several other animals, the cremaster muscle is formed before the testicle 

 descends from the abdomen into the scrotum, being reflected along the guber- 

 naculum testis upwards towards the loins. Mr. Hunter could not, it is true, 

 verify the same observation on the human subject, but he is disposed, from 

 analogy, to believe that something of the kind exists. H. 



