FORM OF THE PENIS. INTEGUMENTS. 955 



THE PENIS. 



The penis, which supports the greater part of the urethra in the male, 

 ia composed principally of an erectile tissue, arranged in masses which 

 occupy three loug and nearly cylindrical compartments. Of these, two, 

 named corpora cavernosa peuis, placed side by side, form the principal part 

 of the organ, whilst the other, situated beneath the two preceding, sur- 

 rounds the canal of the urethra, and is named corpus cavernosum urethrce or 

 corpus spongiosum. 



The penis is attached behind to the front of the pubes, and to the pubic 

 arch, by what is termed the root ; in front it ends in an enlargement named 

 the glans, which is structurally continuous with the corpus spongiosum. The 

 intermediate portion or body of the penis, owing to the relative position of 

 its three compartments, has three somewhat flattened sides, and three 

 rounded borders ; its widest side is turned upwards and forwards, and is 

 named the dorsum. The glans penis, which is slightly compressed above 

 and below, presents at its extremity a vertical fissure, the external orifice 

 of the urethra ; its base, which is wider than the body of the penis, is 

 hollowed out below to receive the narrowing extremities of the corpora 

 caveruosa ; its border is rounded and projecting, and is named the corona 

 glandiSj behind which is a constriction named the cervix ; the posterior 

 boundary of the glans thus marked off passes obliquely down on each side 

 of the under surface, and ends behind the urethral opening, in a median 

 fold of skin, named the frcenum. 



The Integuments. The integument of the penis, which is continued from 

 that of the pubes and scrotum, forms a simple investment as far as the 

 neck of the glans. At this part it leaves the surface and is doubled 

 up in a loose cylindrical fold, constituting the prepuce or foreskin. The 

 inner layer of this fold returns to the penis behind the cervix, where it 

 is firmly attached ; and the integument, becoming thus again adherent, is 

 continued forwards over the corona and glans, as far as the orifice of the 

 urethra, where it meets with the mucous membrane of the urethra, and 

 behind that orifice forms the frcenum of the prepuce. Upon the body of the 

 penis the skin is very thin, entirely free from fat, and, excepting at the 

 root, from hairs also ; in these respects differing remarkably from that on 

 the pubes, which is thick, covers a large cushion of fat, and, after puberty, 

 is beset with hairs : the skin of the penis is moreover very movable and 

 distensible, and is dark in colour. At the free margin of the prepuce the 

 integument changes its character, and approaches to that of a mucous 

 membrane, being red, thin and moist. Numerous sebaceous glands are 

 collected round the cervix of the penis and corona ; they are named the 

 glands of Tyson (glandulse ordoriferse). Their secretion has a peculiar odour, 

 and was formerly supposed to constitute the white smegma prceputii, which 

 tends to collect beneath the foreskin ; but that substance consists princi- 

 pally of epithelial cells cast from the opposed cuticular surfaces. 



Upon the surface of the glans penis the integument again changes its 

 character ; it ceases to contain glands, but its papillae are highly developed 

 and extremely sensitive, and it adheres most intimately and immovably to 

 the spongy tissue of the glans. 



Beneath the skin, on the body of the penis, the ordinary superficial fascia ia 

 very distinct ; it is continuous with that of the groin, and also with the dartoid 

 tissue of the scrotum. Near the root of the organ there is in front a dense 

 band of fibre-elastic tissue, named the suspensory liyament, lying amongst 



