There appears to be no limit to the age at which spontaneous masturbation may begin to appear.  I have already referred to the practice of thigh-rubbing in infants under one year of age.  J.P.  West has reported in detail 3 cases of masturbation in very early childhood—­2 in girls, 1 in a boy—­in which the practice had been acquired spontaneously, and could only be traced to some source of irritation in pressure from clothing, etc.[303] Probably there is often in such cases some hereditary lack of nervous stability.  Block has recorded the case of a girl—­very bright for her age, though excessively shy and taciturn—­who began masturbating spontaneously at the age of two; in this case the mother had masturbated all her life, even continuing the practice after marriage, and, though she succeeded in refraining during pregnancy, her thoughts still dwelt upon it, while the maternal grandmother had died in an asylum from “masturbatory insanity.”

Freud considers that auto-erotic manifestations are common in infancy, and that the rhythmic function of any sensitive spot, primarily the lips, may easily pass into masturbation.  He regards the infantile manifestations of which thumb-sucking is the most familiar example (Luedeln or Lutschen in German) as auto-erotic, the germ arising in sucking the breasts since the lips are an erogenous zone which may easily be excited by the warm stream of milk.  But this only occurs, he points out, in subjects in whom the sensitivity of the lip zone is heightened and especially in those who at a later age are liable to become hysterical.[304] Shuttleworth also points out that the mere fidgetiness of a neurotic infant, even when only a few months old, sometimes leads to the spontaneous and accidental discovery of pleasurable sexual sensations, which for a time appease the restlessness of nervous instability, though a vicious circle is thus established.  He has found that, especially among quite young girls of neurotic heredity, self-induced excitement, often in the form of thigh-friction, is more common than is usually supposed.[305]

Normally there appears to be a varying aptitude to experience the sexual organism, or any voluptuous sensations before puberty.  I find, on eliciting the recollections of normal persons, that in some cases there have been voluptuous sensations from casual contact with the sexual organs at a very early age; in other cases there has been occasional slight excitement from early years; in yet other cases complete sexual anaesthesia until the age of puberty.  That the latter condition is not due to mere absence of peripheral irritation is shown by a case I am acquainted with, in which a boy of 7, incited by a companion, innocently attempted, at intervals during several weeks, to produce erection by friction of the penis; no result of any kind followed, although erections occurred spontaneously at puberty, with normal sexual feelings.[306]

    I am indebted to a correspondent for the following notes:—­