Tattooing often reveals the psychology, habits, and vices of the individual. The tattooing on pederasts usually consists of portraits of those with whom they have unnatural commerce, or phrases of an affectionate nature addressed to them. A pederast and forger examined by Professor Filippi was tattooed on his forearm with a sentimental declaration addressed to the object of his unnatural desires; a criminal convicted of rape was covered with pictorial representations of his obscene adventures. From these few instances, it is apparent that these personal decorations are of the utmost value as evidence of hidden vices and crimes.
_Wrinkles._ We have already spoken of the abundance and precocity of wrinkles in born criminals. They are also a characteristic of the insane.
The following are of special importance: the vertical and horizontal lines on the forehead, the oblique and triangular lines of the brows, the horizontal or circumflex lines at the root of the nose and the vertical and horizontal lines on the neck. (The ferocious leader of a band of criminals at twenty-five, and a savage murderer under thirty years of age.)
_Beard._ The beard is scanty in born criminals and often altogether absent in epileptics. On the other hand, it is common in insane females and in normal women after the menopause. Degenerates of both sexes frequently manifest characteristics of the opposite sex in the distribution of hair on the body. A tuft of hair in the sacro-lumbar region, suggestive of the tail of the mythological faun, is frequently found in epileptics and idiots, and in some cases the back and breast are covered with thick down which makes them resemble animals.
The hair covering the head is generally thick and dark, the growth is often abnormal with square or triangular zones growing in a different direction from the rest, or in small tufts like those inserted in a brush. Still more frequently do we find anomalies in the position of the vortex, or that point whence the hair-growth diverges circularly, which in normal persons is nearly always situated on the crown. In degenerates it is frequently on one side of the head and in cretins on the forehead. Precocious greyness and baldness are common in the insane criminals, and cretins, on the contrary, show these initial signs of senility at a much later period than normal persons.