In temporary insanity, in fury, or in grief, the lower animals have been noticed by naturalists to mutilate themselves.
Self-mutilation in man is almost invariably the result of meditation over the generative function, and the great majority of cases of this nature are avulsions or amputations of some parts of the genitalia.

The older records are full of such instances.

Benivenius, Blanchard, Knackstedt, and Schenck cite cases.

Smetius mentions castration which was effected by using the finger-nails, and there is an old record in which a man avulsed his own genitals.

Scott mentions an instance in which a man amputated his genitals and recovered without subsequent symptoms.