738 MALE GENERATIVE ORGANS. 



lying immediately beneath the mucous membrane. The portion of the bulb 

 below the urethra presents a partial division into two lobes, being marked 

 externally by a linear raphe, whilst internally there projects inwards, for a short 

 distance, a thin fibrous septum, most distinct in early life. 



Structure. The corpus spongiosum consists of a strong fibrous envelop, inclosing 

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

 envelop is thinner, whiter in color, and more elastic than that of the corpus 

 cavernosum. The trabeculre are delicate, uniform in size, and the meshes between 

 them small ; their long diameter, for the most part, corresponding with that of 

 the penis. A thin layer of muscular fibres, continuous behind with those of the 

 bladder, forms part of the outer coat of the corpus spongiosum. 



Erectile tissue consists essentially of an intricate venous plexus, lodged in the 

 interspaces between the trabeculse. The veins forming this plexus are so 

 numerous, and communicate so freely with one another, as to present a cellular 

 appearance when examined by means of a section; their walls are extremely thin, 

 and lined by squamous epithelium. The veins are smaller in the glans penis, 

 corpus spongiosum, and circumference of the corpora cavernosa, than in the central 

 part of the latter, where they are of large size, and much dilated. They return 

 the blood by a series of vessels, some of which emerge in considerable numbers 

 from the base of the glans penis, and converge on the dorsum of the organ to form, 

 the dorsal vein ; others pass out on the upper surface of the corpora cavernosa, 

 and join the dorsal vein ; some emerge from the under surface of the corpora 

 cavernosa, and, receiving branches from the corpus spongiosum, wind round the 

 sides of the penis to terminate in the dorsal vein ; but the greater numbef pass 

 out at the root of the penis, and join the prostatic plexus and pudendal veins. 



The arteries of the penis are derived from the internal pudic. Those supplying 

 the corpora cavernosa are the arteries of the corpora cavernosa, and branches from 

 the dorsal artery of the penis, which perforate the fibrous capsule near the fore 

 part of the organ. Those to the corpus spongiosum are the arteries of the bulb. 

 Additional branches are described, by Kobelt, as arising from the trunk of the 

 internal pudic ; they enter the bulbous enlargement on the corpora cavernosa and 

 corpus spongiosum. The arteries, on entering the cavernous structure, divide into 

 branches, which are supported and inclosed by the trabecula? ; according to Mil Her, 

 some of these branches terminate in a capillary network, which communicates with 

 the veins as in other parts ; whilst others are more convoluted, and assume a tendril- 

 like appearance ; hence the name, helicine arteries, which is given to these peculiar 

 vessels. The helicine arteries are most abundant in the back part of the corpora 

 cavernosa and corpus spongiosum ; they have not been seen in the glans penis. 

 The existence of these vessels is denied by Valentin, who describes the smallest 

 branches of the arteries as terminating by wide, funnel-shaped orifices, which open 

 directly into the venous cavities. 



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

 terminate in the inguinal glands, the latter emerge from the corpora cavernosa 

 and corpus spongiosum, and, passing beneath the pubic arch, join the deep lym- 

 phatics of the pelvis. 



The nerves are derived from the internal pudic nerve and the hypogastric plexus. 

 On the glans and bulb, some filaments of the cutaneous nerves have Pacinian 

 bodies connected with them. 



THE TESTES. 



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

 situated in the scrotum, being suspended by the spermatic cords. Each is of an 

 oval form, compressed laterally and behind, and having an oblique position in the 

 scrotum ; the upper extremity being directed forwards and a little outwards ; the 

 lower, backwards and a little inwards ; the anterior convex border looks forwards 

 and downwards, the posterior or straight border, to which the cord is attached, 

 backwards and upwards. 



