THE PROSTATE GLAND. 241 



exhibit local cushion-like thickenings of the intima, similar to but less marked 

 than those seen in the arteries. The erectile tissue of the corpus spongiosum 

 includes that of the urethral mucosa, produced by the unusual abundance of 

 the venous channels, and that of the spongy body proper, a surrounding tract 

 having much the character of the corpora cavernosa. The spongy body is 

 distinguished by the stoutness of its trabeculae and the small size of its venous 

 spaces; further, by the absence of arteries opening directly into the lacunae. 



The lymphatics of the penis are disposed as superficial and deep 

 vessels. The latter are particularly numerous in the periphery of the glans 

 and send tributaries to aid in forming a deep dorsal lymph-stem along the 

 corresponding vein. The superficial lymphatics are directed chiefly to a 

 superficial dorsal trunk that accompanies the superficial vein and begins by 

 the confluence of networks within the integument. 



The nerves of the penis include both spinal and sympathetic fibres, 

 the former from the ilio-inguinal and the pudic nerves and the latter from 

 the hypogastric plexus. The integument of the body and glans and prepuce 

 is supplied by the dorsal nerves. The cylinders of cavernous tissue also 

 receive twigs from the pudic nerves, the bulbar branches of which pass to 

 the bulbus urethrae and in addition supply the mucous membrane of the 

 urethra. Each corpus cavernosum receives a deep branch from the dorsal 

 nerve. The sympathetic fibres, destined for the blood-vessels and unstriped 

 muscle of the erectile tissue, continue from the hypogastric to the cavernous 

 plexus; here, joining the dorsal nerves of the penis, twigs are sent to the 

 corpora cavernosa, some terminating in the spongy body. Close networks 

 of nonmedullated fibres have been followed into the involuntary muscle 

 within the blood-vessels and the trabeculae of the erectile tissue. Certain 

 cerebro-spinal fibres, known as the nervi erigentes, from the third and fourth 

 sacral nerves, are supposed to be especially concerned in erection; they are 

 conveyed, in company with the sympathetic fibres, along the paths of the 

 cavernous plexus. In addition to the more usual terminations, the skin of 

 the glans and prepuce is provided with special nerve-endings tactile corpus- 

 cles and genital corpuscles lying within the papillae and the Pacinian bodies 

 within the subcutaneous stratum. The path of the sensory impulses lies 

 within the dorsal nerves of the penis. 



THE PROSTATE GLAND. 



Although developed as an appendage of the urinary tract and not directly 

 as part of the sexual apparatus, the prostate is functionally so closely related 

 to the generative organs, that it may appropriately be regarded as one of the 

 accessory glands, the others being the bulbo-urethral glands. 



The prostate gland resembles in form an inverted Spanish chestnut, the 

 base being attached to the under surface of the bladder and the small end, or 

 apex, directed downwards. It is traversed from base to apex by the urethra, 

 and from behind to the urethra by the ejaculatory ducts. The prostate is a 

 tubo-alveolar gland and made up of three chief components the connective 

 tissue framework, the involuntary muscle, and the glandular tissue. Of these 

 the glandular tissue constitutes a little more than one half of the entire organ 

 and the connective tissue and the muscle each somewhat less than one quarter. 



The connective tissue framework includes an external fibro-elastic 



envelope, the capsule proper, and a median septum which encloses and blends 



with the walls of the urethra. Between these denser lamellae, numerous 



radiating partitions subdivide the organ into from thirty to forty pyramidal 



16 



