914 



PENIS. 



Krause,* having recourse to the chemical in- 

 vestigation of this substance in man, came to a 

 very different conclusion from that of Miiller. 

 " After many hours boiling," he says, " the 

 fibres of the corpus cavernosum of man are con- 

 verted almost wholly into gelatine, whereas, in 

 boiling muscular substance, the cellular sub- 

 stance alone suffers this change, and the mus- 

 cular fibre becomes still more evident. Again, 

 if a portion of the boiled internal structure of 

 the corpus cavernosum, not as yet reduced to 

 jelly, and a portion of muscular fibre boiled for 

 an equally long time, be examined with the 

 microscope, the difference is more apparent 

 than in the fresh condition. A solution of the 

 fibrous structure of the corpus cavernosum 

 (previously well washed with water) in concen- 

 trated acetic acid is not precipitated by ferro- 

 cyanate of potash, whereas a similarly treated 

 solution of muscular fibre affords an abundant 

 white or blueish-white precipitate." In reply 

 to Krause's analysis, Miiller remarks: " it will 

 be seen that our investigation on the corpus 

 cavernosum of the horse gives a precisely op- 

 posite result to that of Krause on the same part 

 in man; whence it follows, either that Krause 

 has examined this peculiar substance mingled 

 with other structures, as cellular tissue, &c., or 

 that it does not exist in man. Had Krause 

 investigated the tissue described by me in the 

 penis of the horse, he would undoubtedly have 

 met with the same results which I have so 

 constantly obtained." 



Besides the fibres of contractile fibrous tissue 

 distributed through the panetes of the venous 

 canals, the arteries and nerves of the corpus 

 cavernosum also ramify in the intercellular sub- 

 stance in their course through the structure of 

 the penis. 



The corpus spongiosum (corpus cavernosum 

 urethra;) is a lengthened cylindrical body situ- 

 ated along the under surface of the corpus 

 cavernosum in its inferior groove, and forming 

 the inferior border of the penis. It commences 

 posteriorly between and beneath the crura of 

 the penis by a rounded enlargement, the bulb, 

 and terminates at the extremity of the organ in 

 the glans penix ; the intermediate portion is 

 cylindrical in form, and enlarges gradually from 

 its middle towards the two extremities, the bulb 

 posteriorly and the base of the glans in front. 



The glans penis resembles in form an oblique 

 section of a cone, rounded at its apex ; it is 

 slightly compressed from above downwards, 

 and is terminated posteriorly by a prominent 

 border, the corona glavdis. At the apex of the 

 glans is a small vertical slit, the ineatus urinu- 

 rim, which is bounded by two more or less 

 protuberant labia, and extending backwards 

 along the middle of its under surface is a 

 grooved raphe, to which is attached thefracnum 

 praeputii. The colour of the glans penis pre- 

 sents a deeper tint of red than that of the 

 neighbouring integument, and is invested by 

 mucous membrane. At the meatus urinarius 

 this membrane is continuous with the mucous 

 lining of the urethra, and at the base of the 



* Hcckcr's Annaleu, February, 1831. 



glans is reflected on the inner surface of the 

 prepuce, as far as the free margin of the latter. 

 The corona glandis is studded by a number of 

 small papillary projections, formed by sebaceous 

 glands, meglandula Tysoni(udoriferte), which 

 pour out a whitish, unctuous, and strongly 

 scented secretion to lubricate the surface of the 

 glans and prepuce. Behind the glans is a 

 deep furrow, bounded by the corona in front, 

 and posteriorly by the fold of the prepuce. 



Examined with the microscope, the surface, 

 of the glans penis is found raised into small 

 rounded papillae which cover every part of its 

 surface. 



The corpus spongiosum is traversed in the 

 direction of its length by the common urino- 

 sexual canal, the urethra. At the commence- 

 ment of the corpus spongiosum, the urethra 

 occupies a groove upon the upper surface of 

 the bulb ; further on it enters the substance of 

 the body, but lies much nearer to the upper 

 than the lower surface, while at i)s termination 

 it occupies the lower segment of the glans. 



The corpus spongiosum resembles the corpus 

 cavernosum in being composed of a plexiform 

 vascular structure enclosed in a dense and 

 strong fibrous investment, but it differs from 

 that body in the smaller size of its venous 

 canals, the thinness of its fibrous tunic, and 

 especially in enclosing the canal of the urethra. 

 The vascular structure of the corpus spongio- 

 "sum, like that of the corpus cavernosum, con- 

 sists of dilated veins of smaller size than those 

 of the latter body, and separated in the same 

 manner by membranous parietes. In the glans 

 penis the veins are even smaller than in the 

 body of the corpus spongiosum, particularly 

 near the surface and around the embossed 

 border of the corona glandis. The contractile 

 fibrous tissue appears to me to be similarly 

 distributed between the veins, but is smaller in 

 quantity than in the corpus cavernosum. Mayer 

 also describes tins tissue as existing in the 

 parietes of the venous canals of the corpus 

 spongiosum, but Mu'ller denies its existence in 

 that body, and observes, " in the corpus spon- 

 giosum, where Mayer also admits this sub- 

 stance, it is not present, at least it is perfectly 

 clear that it does not exist in that body in the 

 horse." The fibrous tunic of the corpus spon- 

 giosum is continuous at its bulb with the ante- 

 rior layer of the deep perineal fascia. 



The 7HUCOHS membrane of the penis is the 

 lining of the urethra and the investment of the 

 glans and internal surface of the prepuce. In 

 the canal of the urethra, near the extremity of 

 the organ, it is of a deep pink colour, and be- 

 comes gradually paler as it approaches the 

 bladder. By the contraction of the coats of the 

 urethra it is thrown into longitudinal folds; 

 and it is furnished with numerous small lacuncc, 

 which are especially numerous along the upper 

 surface of the cylinder. The openings of these 

 lacuna; are directed forwards, and are calcu- 

 lated to afford an impediment to the passage of 

 any small instrument into the bladder by catch- 

 ing its point. One lacuna of larger size than 

 the rest is situated in the upper wall of the 

 urethra, at about an inch and a half from the 



