. 124 PROP. w. B, BEifHAM ON THE [May 21, 



destined for the glans is not in the mid-dorsal line, but consists of 

 a right and left group of veins and arteries, lying on either side of 

 the upper surface of the penis. Only for a short space, just behind 

 the attachment of the penial sheath, do the two bunches of vessels 

 widen out so as to meet dorsally, but almost immediately they 

 separate again as the " glans " is entered, and take up a still more 

 distinctly lateral position (PI. X. fig. 17, Bv). 



The ventral surface of the c. cavernosum embraces, as usual, the 

 corpus spongiosum, in which the urethra is contained in a slightly 

 asymmetrical position. 



In transverse section the c. spongiosum is ^ inch in height by 

 I inch across. 



While the tunic of the c. cavernosum is very thick and dense, 

 that of the c. spongiosum is quite thin, and to the naked eye is not 

 distinguishable from the tissue of the spongy body itself. 



As the distal region or glans is approached the relative sizes of 

 the parts change. The glans is an elongated cylindrical cone, 

 terminating in a blunt and slightly upturned point, the slit-like 

 urinogenital pore, which is | inch in length, being subterminal. In 

 the preserved specimen the skin of the glans has a yellowish tint, is 

 smooth but much wrinkled transversely, owing no doubt to shrinkage. 

 Soon after the c. cavernosum has entered the glans, it undergoes a 

 considerable reduction in size : thus, at a distance of 6 inches from 

 the tip (PI. X. fig. 17) it is, in transverse section, circular in outline, 

 with a diameter of only | inch, while the c, spongiosum has 

 slightly increased in size. Pui-ther forwards, two inches from 

 the tip (PI. X. fig. 18), the cavernous body has almost disappeared. 

 It is but I inch in diameter, while the spongy body is now | inch 

 across, and is practically circular. The rest of the substance of the 

 penis is now occupied by fibrous tissue with abundant vessels, chiefly 

 laterally placed, derived from the previously mentioned dorso- 

 lateral " plexus." 



The urethra has enlarged, and here commences the usual dila- 

 tation to form the " fossa navicularis." Turning to the proximal 

 region, we find a very interesting condition of affairs. After 

 dissecting away the muscles — or rather by slicing them away — 

 the usual crura penis (c. c. spongiosi) are exposed (PI. X. fig. 19), 

 each embedded in a muscle fchat appears to be the " erector penis " 

 (or M. ischio-cavernosus). But the c. spongiosum instead of 

 terminating posteriorly in the usual bulb at the angle of origin of 

 the crura, bifurcates ; and each limb or the cms c. spongiosi is enclosed 

 in one of the " accelei-ator urinae " muscles (or M. bulbo-cavernosus), 

 within which it enlarges to several times its former size (PI. XI. 

 fig. 20). Bach crus of the spongy body is 2| inches in length, and 

 is as long as the crus penis : it is here irregularly oval in section, 

 and measures g by | inch across. 



The crus c. spongiosi lies ventrad and mediad of the crus c. 

 cavernosi of its side, and the upper and external face rests against 

 the tough tunic of the latter, while on the other three sides it is 

 enveloped in muscle. 



