446 DEVELOPMENT OF THE [SECT. 201. 



The smooth muscular fibres of the corpora cavernosa are exceedingly 

 beautiful in the penis of the horse and elephant, but are not wanting even in 

 other mammalia. — The helicine arteries have commonly been rejected by 

 anatomists, since the statement of Valentin and Henle, that they are produced 

 artificially, by the rolling up of the cut ends of the trabeculse, or by the spon- 

 taneous retraction of certain arteries in the stretched trabeculse. I am con- 

 vinced, however, that their rejection cannot be justified, and that the helicine 

 arteries do truly exist. I am satisfied, moreover, that they very frequently 

 end in fine, almost capillary vessels, as even J. Midler pointed out ; but I do not 

 believe that this is the exceptional arrangement that it appeared to its dis- 

 coverer, indeed I am disposed to regard it as very common, and that the 

 termination in culs de sac is constantly more apparent than real ; still I will 

 not undertake to assert positively that such csecal endings do not exist — per- 

 haps Midler may be right in this respect also. By another observer, again, 

 Arnold, the helicine arteries were taken for simple loops of vessels ; but my 

 own observations by no means bear out this view, though I have once seen 

 such a loop in the situation of these arteries. 



The corpus spongiosum urethrse, in its most anterior portion and in the 

 glans, is stated by Jarjeivay to have the characters of a ' rete mirabile ' of 

 veins. — In the envelope of the corpora cavernosa penis, two layers of mus- 

 cular fibres have been described by Ellis, the outer longitudinal and the inner 

 circular, the fasciculi forming a network with narrow interstices ; the inner 

 layer is stated to be continued into the septum penis. I record these state- 

 ments simply, without making myself responsible for them, as up to this 

 time no such muscular fibres have come under my notice in this situation. — 

 Jarjavuy makes a distinction between the glands of the membranous part of 

 the urethra and those of the spongy portion : he confines the name of Little's 

 glands to the former, and names the others 'lacunae of Morgagni'' ; this is 

 not a justifiable division, as the glands are of one- and the same nature, al- 

 though they occur in a variety of forms, simple and compound. The larger 

 glands of the spongy part of the urethra are five to- twenty- two in number, 

 and are mostly arranged in a single row in the middle of the upper wall. The 

 smaller glands are found in the upper wall also, but principally on the sides. 



§ 201. Physiological Remarks. — The development of the testicles 

 commences in the second month, and takes place from an inde- 

 pendent blastema, that appears at the inner side of the Wolffian 

 bodies, the male sexual glands being at first exactly similar in form 

 to the ovaries. Subsequently, when the "Wolffian bodies begin to 

 disappear, certain of its canals lose their Malpighian corpuscles, 

 and become connected with the testicle, to form the epididymis; 

 while, at the same time, the excretory duct of the gland is trans- 

 formed into the vas deferens. By a process not yet accurately 

 explained, involving the agency of the gubernaculum, the testicle, 

 with its peritoneal covering, then descends into the scrotum. The 

 gubernaculum, I find with Donders {Ned. Lancet, 1849, P* 3^ 2 )> i s 



