1972 HUMAN ANATOMY. 



Variations. — Apart from the unimportant individual differences due to age, growth, and 

 sexual activity, the variations of the penis are for the most part referable to imperfect develop- 

 ment and are recognized as malformations rather than as anatomical deviations. The explana- 

 tion of many of these conditions is supplied by the developmental history of the structures 

 involved (page 2044) . 



PRACTICAL CONSIDERATIONS : THE PENIS. 



The size of the penis bears less constant relation to general physical develop- 

 ment than does any other organ of the body. The normal average size of the flaccid 

 penis of the adult is about three inches in circumference and from three and a half to 

 four inches in length, measured from the suspensory ligament. When erect, this 

 length increases to about six and a half inches and the circumference to, three and a 

 half or more. 



Absence of the penis may occur, but is rare unassociated with other anomalies. 

 Apparent absence (concealed penis) may be due to the subcutaneous situation of an 

 atrophic or undeveloped organ which may be palpated through the skin and revealed 

 by an incision. 



Micropenis (infantile penis) is not uncommon, and varies in degree from a mere 

 failure to attain quite the average size (annoying chiefly to sexual neurasthenics) to a 

 retention throughout life of the dimensions and development normal in early childhood 

 or infancy. Occasionally in such cases, after puberty and following physiological 

 activity of the organ, rapid growth takes place and conditions approximating normal- 

 ity may result. 



Megalopenis. — As has already been observed, the size of the organ bears no 

 constant relation to the size or strength of the individual. In congenital imbeciles it 

 is often of unusual size, and in dwarfs and hunchbacks it is not uncommonly devel- 

 oped, not only out of proportion to the other parts of the organism, but beyond even 

 the average for individuals of normal growth. Hypertrophy of the penis is at times 

 an inconvenience, and may even be a source of danger, since an excessive develop- 

 ment predisposes to abrasions and fissures through which inoculation with venereal 

 diseases may occur. 



Double penis has been recorded in a few instances, in at least two of whith each 

 organ was functionally perfect. 



The skin of the penis is thin and delicate (to maintain the sensitiveness of the 

 organ), and is lax and elastic (to permit of its changes in size). On account of these 

 qualities abrasions are not unusual, and through them syphilitic infection frequently 

 takes place. 



The loose, plentiful layer of subcutaneous connective tissue permits of enormous 

 cedematous swelling as a result of ordinary staphylococcic or streptococcic (pyogenic 

 or erysipelatous) infection; its abundance in conjunction with the elasticity of the skin, 

 accounts for the disappearance of the penis in cases of very large scrotal hernia, in 

 hydroceles of similar size, and in elephantiasis scroti. 



Anterior to the corona the skin is modified and resembles a mucous mem- 

 brane, at the meatus becoming continuous with the mucosa of the urethra. The line 

 of demarcation between the ordinary and modified cutaneous surfaces is not, however, 

 so distinct as on the lips or the nostrils, the passage of one surface into the other more 

 closely resembling that which takes place at the margin of the anus. On the proxi- 

 mal face of the corona the subcutaneous tissue is still abundant. Over the glans it 

 practically disappears and the modified integument closely embraces the erectile tissue 

 of the expanded anterior extremity of the corpus spongiosum. 



Chancres anterior to the corona (except at the frenum) are apt to exhibit the 

 variety of induration known as "laminated" or "parchment-like," corresponding to 

 a sclerosis limited to the papillary layer of the derma and to the vascular net-work of 

 the papillae. At the frenum, corona, or cervix, where the cellular tissue is abundant, 

 ' ' nodular' ' induration — a sclerosis of the whole thickness of the derma, of the subder- 

 moid areolar tissue, and of the associated vascular net- work, which is much larger 

 than the superficial or papillary supply — is apt to occur, and is, as the name indicates, 

 deeper, thicker, and harder. On the skin of the penis chancres are apt to be exten- 

 sive in area, but are limited in depth by the firm, resistant fascia penis. 



