160 CELLS OF THE CORPORA CAVERNOSA. 



of a whitish ligamentous appearance and great firmness. They 

 are filled with a substance of a cellular structure, which is occa- 

 sionally distended with blood. The crura of these cylindrical 

 bodies, which are attached to the crura of the ischium and 

 pubis, are small and pointed at the commencement, and are 

 united to the periesteum of the bones. In their progress up- 

 wards they enlarge, and at the symphysis of the pubis they 

 unite so as to form an oblong. body, which retains the appear- 

 ance of a union of two cylinders applied to each other length- 

 ways ; for above, there is a superficial groove passing in that 

 direction, which is occupied by a large vein : and below there 

 is a much deeper groove, in which the urethra is placed. Be- 

 tween these grooves is a septum which divides one side of the 

 penis from the other. It appears to proceed from the strong 

 membrane which forms the penis, and is composed of bundles 

 of fibres, which pass from one groove of the penis to the other, 

 with many intervals between them, through which blood or in- 

 jection passes very freely. Sometimes these bundles of fibres, 

 with their intervals, are so regularly arranged, that they have 

 been compared to the teeth of a comb. This septum extends 

 from the union of the two crura to their termination. 



It is called the Septum pectiniforme ; the internal between 

 its bundles of dense cellular fibres, become so great and so 

 numerous in the anterior half, that it ceases to divide the penis 

 into two corpora cavernosa. Anatomists now consider the cor- 

 pus cavernosum as one body imperfectly divided by the septum. 

 It is a distinction, however, without much value. 



Each of these cylinders is penetrated by the main branch of 

 the pubic artery, which is about equal in size to a crow's quill. 

 These arteries enter the corpora cavernosa near their union, and 

 continue through their whole extent, sending off branches in 

 their course ; the turgescence and erection of the penis is un- 

 questionably produced by the blood which flows through these 

 vessels into the penis. 



The interior structure of the penis, when examined in the 

 recent subject, is of a soft spongy nature, and seems stained 

 with blood. If any fluid be injected through the arteries this 



