912 



PENIS. 



the thick and dense dermis of the neighbouring 

 parts of the abdomen and thighs. Its colour 

 is brown, but varies in its depth in different 

 individuals, being darker in those of a dark 

 complexion, and little differing from the skin 

 of the rest of the body in persons of an oppo- 

 site character. As in other parts of the body, 

 it is well provided with sebaceous glands, but 

 these are more numerous in that portion which 

 invests the under part of the organ than in the 

 dorsal region. Near to the free extremity of 

 the penis the integument forms an ample fold, 

 the fore-skin or prepuce (prteputium), which 

 serves to envelope the glans when the organ 

 is in repose, and to increase the investing co- 

 vering when it is distended and enlarged. The 

 prepuce is connected to the glans on its under 

 part by means of a narrow fold termed the 

 Jrnnum praputii, and is lined by mucous 

 membrane. Along the ed^e of the prepuce 

 the mucous membrane is continuous with the 

 skin of the penis ; at the base of the prepuce 

 it is reflected over the glans, and at the summit 

 of the latter is continuous with the mucous 

 membrane of the urethra through the meutus 

 urlnurius. Upon the under part of the glans 

 the mucous membrane enclosing some fibrous 

 tissue constitutes the narrow fold above de- 

 scribed, the franum prseputii. At the base 

 of the body of the penis, the integument is 

 continuous with that of adjoining parts, with 

 the skin of the pubes superiorly, and of the 

 scrotum laterally and beneath. In this situa- 

 tion, moreover, it is altered in its characters ; 

 it is thicker in its texture and furnished with 

 numerous hairs. The latter differ from the 

 hairs of the pubes in taking the direction of 

 the axis of the penis, and in being, unlike the 

 former, perfectly straight. Along the inferior 

 border of the penis the integument presents a 

 somewhat prominent line, which is continuous 

 with the raphe of the scrotum behind and with 

 the franum of the prepuce in front. This is 

 the rap fie of the penis, and indicates the mode 

 of formation of the urethra, by the conjunction 

 of two lateral segments on the middle line. 



The subcutaneous areolar tissue connecting the 

 integument to the body of the penis is extremely 

 lax, and wholly devoid of adipose formation. 

 The laxity of this tissue has the effect of per- 

 mitting an enormous increase of size in the 

 organ without inconvenience ; thus in the state 

 of repose the prepuce usually covers the glans 

 either partially or completely, and protects the 

 mucous membrane from the attrition of dress ; 

 but in the state of erection this duplication is 

 wholly effaced, and the integument rendered 

 tense over the entire organ. In large hernias 

 and in very large tumours of the scrotum again, 

 the integument, from its extreme looseness of 

 attachment, is withdrawn from the penis, and 

 contributes to the investment of the swelling. 

 In this way the whole of the integument is 

 sometimes distended with the tumour, and the 

 penis lies buried in the enlargement ; its situa- 

 tion being only distinguishable by means of a 

 valvular opening, through which the urine 

 trickles. Like all loose cellular tissue which 



is indisposed to the production of fat, the cel- 

 lular tissue of the penis, in a state of inflam- 

 mation, is particularly liable to serous in- 

 filtration, which renders the organ swollen 

 and cedematous. 



The fascia penis is a thin but dense layer 

 of white fibrous tissue, which immediately in- 

 vests the penis, forming for it a kind of sheath r 

 and is continuous with the superficial perineal 

 fascia. On the dorsum penis the fascia covers 

 in the dorsal vessels and nerves, and is closely 

 connected with the aponeurosis of the erectores 

 penis muscles ; indeed it is rendered tense and 

 stretched over the organ by the action of those 

 muscles. 



The corpus cavernosum forms more than two- 

 thirds of the bulk of the penis; it is usually 

 described as two distinct bodies under the 

 name of corpora cavernosa, but it is more cor- 

 rect to consider it as a single organ divided 

 posteriorly into two parts, and separated in the 

 interior by an imperfect partition. Apart from 

 the other components of the penis the corpus 

 cavernosum represents a lengthened cylinder 

 somewhat flattened from above downwards 

 and grooved along the middle line both upon 

 its upper and under surface; the upper groove 

 lodging the dorsal vein, arteries and nerves,, 

 and the under the corpus spongiosum. Ante- 

 riorly the corpus cavernosum terminates in an 

 oblong and rounded extremity, which is re- 

 ceived into a depression on the posterior surface 

 of the glans; and posteriorly it divides into 

 two rounded and conical processes, about two 

 inches in length, which separate from each 

 other and are firmly inserted into the everted 

 edge of the ramus of the ischium and pubis 

 under the name of crura penis. 



The corpus cavemosum is closely connected 

 to the glans penis and corpus spongiosum by 

 dense areolar tissue and by a few vessels of 

 communication. Behind and inferiorly it is 

 attached to the rami of the ischia by its two 

 crura ; and above it is connected to the sym- 

 physis pubis by means of a strong fibrous liga- 

 ment of a triangular form, the ligamentum 

 suspensorium penis. This ligament is inserted 

 by one border into the fibrous structure cover- 

 ing the svmphysis pubis, and by its base is 

 continuous with the aponeurosis of the erectores 

 penis muscles and with the fascia penis ; the 

 remaining border being free and directed for- 

 wards. In a few rare instances the ligamentum 

 suspensorium penis has been found to contain 

 some muscular fibres. 



The corpus cuvernosum is composed of a 

 cellular structure enclosed in a thick fibrous 

 tunic of great strength. The tunic is con- 

 structed of longitudinal fibres closely inter- 

 woven with each other so as to constitute a. 

 tissue which possesses perfect elasticity, and 

 yields freely to distension up to a certain point, 

 but resists enlargement beyond that limit. From 

 the interior of this tunic are given off a number 

 of fibrous bands and cords ( trabecul<e) which 

 pass in a radiated direction from the middle 

 line of its inferior wall to the rest of the in- 

 ternal circumference of the cylinder, to which 



