238 



SPECIAL HISTOLOGY. 



spongiosa. In the corp. cav. penis, except a few small twigs 

 from the a, dor sails, the a. profunda penis alone run near the 

 septum, surrounded by a sheath of connective tissue continuous 

 with the trabecular network, in fact directly forwards, but 

 giving off a small twig to the bulbs of the crura. In this 

 course they afford numerous, occasionally anastomosing branches 

 to the spongy substance, which, running in a convoluted manner 

 (except at the time of erection) in the axis of the trabecule, ramify 

 in them, and ultimately, without the formation of capillary 

 plexuses open into the venous spaces, by capillaries of 006 — 

 0*0 1'" in diameter. In the posterior part of the penis there 

 are numerous minute arterial trunks, measuring 0-04 — 008'" 

 in diameter, and for the most part lying from 3 — 10 together, 

 as was first observed by J. Miiller; they are contorted and 

 convoluted in a peculiar, tendril-like manner (arterice helicinm), 

 and do not terminate in csecal ends, but, as I have ascer- 

 tained, give off from their clavate extremities minute vessels of 

 0-006 — 0*0r", which, like the other arterial prolongations, are 

 continued further, and terminate in the venous spaces. The 

 arterial ramification is precisely similar, in the corpus cavernosum 



Fig. 262. 



urethra, which is furnished with its supply from the art. 



Fig. 262. Arteries from the corpora cavernosa penis of Man, injected, x 30 diara. 

 1. one of the smaller arteries, with a lateral branch, dividing into two helicine ar- 

 teries, from the extremities of which two very small vessels proceed, and are con- 

 tinued into the delicate trabecule ; 2. five helicine arteries placed on a short stem of 

 a larger arterial division ; from two of these, fine vessels are seen to be given off, the 

 others appear to terminate in caecal ends : a, trabecular tissue, here presenting the 

 form of sheaths to the arterial trunks and helicine arteries ; b, wall of the arteries. 



