THE TESTES. 1153 



Structure. The corpus spongiosum consists of a strong fibrous envelope, 

 enclosing a trabecular structure, which contains in its meshes erectile tissue. The 

 fibrous envelope is thinner, whiter in color, and more elastic than that of the 

 corpora cavernosa. The trabectilse are delicate, uniform in size, and the meshes 

 between them small, their long diameter, for the most part, corresponding with 

 that of the penis. The external envelope or outer coat of the corpus spongiosum 

 is formed partly of unstriped muscular fibre, and a layer of the same tissue imme- 

 diately surrounds the canal of the urethi'a. 



The lymphatics of the penis consist of a superficial and deep set ; the former 

 are derived from a dense network on the skin of the glans and prepuce and from 

 the mucous membrane of the urethra, and terminate in the superficial inguinal 

 glands ; the latter emerge from the corpora cavernosa and corpus spongiosum, and, 

 passing beneath the pubic arch, join the deep lymphatics of the pelvis. 



The nerd 1 * are derived from the internal pudic nerve and the pelvic plexus. On 

 the glans and bulb some filaments of the cutaneous nerves have Pacinian bodies 

 connected with them, and, according to Krause, many of them terminate in a 

 peculiar form of end-bulb. 



Surgical Anatomy. The penis occasionally requires removal for malignant disease. 

 Usually, removal of the ante-scrotal portion is all that is necessary, but sometimes it is requisite 

 to remove the whole or<ran from its attachment to the rarni of the os pubis and ischium. The 

 former operation is performed either by cutting off the whole of the anterior part of the penis 

 with one sweep of the knife, or, what is better, cutting through the corpora cavernosa from the 

 dorsum, and then separating the corpus spongiosum from them, dividing it at a level nearer the 

 glans penis. The mucous membrane of the urethra is then slit up, and the edges of the flap 

 attached to the external skin, in order to prevent contraction of the orifice, which would other- 

 wise take place. The vessels which require ligature are the two dorsal arteries of the penis, the 

 arteries of the corpora cavernosa, and the artery of the septum. When the entire organ requires 

 removal the patient is placed in the lithotomy position, and an incision is made round the root 

 of the penis, and carried down the median line of the scrotum as far as the perinaeum. The 

 two halves of the scrotum are then separated from each other, and, a catheter having been intro- 

 duced into the bladder as a guide, the membranous portion of the urethra is separated from the 

 corpus spongiosum and divided, the catheter having been withdrawn, just behind the bulb. The 

 su<i ien;< ry ligament is now severed, and the crura separated from the bone with a periosteum 

 scraper, and the whole penis removed. The membranous portion of the urethra, which has not 

 been removed, is nmv to be attached to the skin at the posterior extremity of the incision in 

 the periiuvum. The remainder of the wound is to be brought together, free drainage being 

 provided for. 



THE TESTES AND THEIR COVERINGS (Fig. 738). 



The Testes are two glandular organs, which secrete the semen ; they are sit- 

 uated in the scrotum, being suspended by the spermatic cords. At an early 

 period of foetal life the testes are contained in the abdominal cavity, behind the 

 peritoneum. Before birth they descend to the inguinal canal, along which they 

 ]>as> with the spermatic cord, and, emerging at the external abdominal ring, they 

 descend into the scrotum, becoming invested in their course by numerous coverings 

 derived from the serous, muscular, and fibrous layers of the abdominal parietes, 

 as well as by the scrotum. The coverings of the testes are the 



Skin \ ( 



TA > ocrotum. 



Dartos J 



Intel-columnar, or External spermatic fascia. 



Cremasteric fascia. 



Infundibuliform, or Fascia propria (Internal spermatic fascia). 



Tunica vaginalis. 



The Scrotum is a cutaneous pouch which contains the testes and part of the 

 spermatic cords. It is divided superficially into two lateral halves by a median line, 

 or raphe, which is continued forward to the under surface of the penis and backward 

 along the middle line of the perinaeum to the anus. Of these two lateral portions, the 

 left is longer than the right, and corresponds with the greater length of the spermatic 

 cord on the left side. Its external aspect varies under different circumstances : 

 73 



