Moderate masturbation seems to be almost a natural phenomenon. Even among animals various forms of spontaneous solitary sexual excitement are observed.
Dogs masturbate by rubbing the organ with their hind-feet, or by crossing the hind-legs or lambendo fascinum lingua.
The stag, when in heat, rubs his penis against trees until he effects ejaculation.
Porocz saw in a zoological garden an elephant, who was in the habit of masturbating himself so often that he undermined his health and had to be sold.
Prange (Revue vétér. 1856) describes a stallion that with his mentulato fascino could reach his forelegs and thus rub the organ against them. In this way he induced three to four ejaculations daily.
The author observed a baboon in the zoological park se constuprantem by quickly and repeatedly pulling with his fore-foot or hand the prepuce until ejaculation took place.
Masturbation is further found among peoples of nearly every race, however natural the conditions are under which men and women live. Masturbation was known among all races at every period of history. It is reported that the great Cynic Diogenes practised autoeroticism publicly in his tub.
Schools, academies, educational institutions, dormitories of colleges, factories or prisons are hot-beds of masturbation. Prof. Schiller published the observations in a certain gymnasium (collegiate high school) where the boys had holes in the pockets of their trousers ad stuprum mutuum faciendum during the lessons, in the presence of their professors.
Thomalla knows of a boarding school where bets are made among the boys on the skill of their exercitatio stuprosa. The boy who can induce the ejectio seminis the quickest receives the prize.
Walter Benseman (Public School and Gymnasium) describes the most deplorable conditions existing in a great many boarding schools in England.
In France, Deville and Tarnowsky found the spread of masturbation in schools, colleges and pensionates to be enormous.
Male masturbation, as a rule, is effected by fricando glandem manu. Hence such mishaps, as often happen in woman, are of rare occurrence. Still many queer objects were found in the male urethra or bladder, such as quills, pencils, penholders, blades of straw, knitting needles, pieces of bougies or of catheters, ear-spoons, tooth-picks, all introduced for masturbating purposes. Senn removed in a young man, nineteen years of age, a stem of a plant from the bladder, which was introduced into the bladder for autoerotic purposes. The author removed a pencil from the pars membranacea of a boy of eighteen, through an incision in this part.