Erections occur during childhood; they have been observed even in infancy. They sometimes result from external stimuli, especially of a pathological nature, such as a strictured prepuce, or inflammatory states of the penis. Occasionally in the child, as normally in the adult male, distension of the bladder with urine leads to erection of the penis. Although in these cases the erection is not induced by sexual processes, it is nevertheless not devoid of significance in relation to the sexual life. The sensations in the genital organs to which the pathological stimuli give rise are further increased by the erection, and the child's attention is therefore increasingly drawn to his sexual organs. His attention may, of course, be directed to his genital organs by such stimuli as those we have described, even though these latter do not lead to the occurrence of erection. By such sensations, the child is very readily induced to manipulate his genital organs. Just as the little child soon learns to scratch other itching regions of the skin, so also he learns to scratch his genital organs when these are the seat of an itching eruption, or when in any other way irritating sensations arise in this region. Pflueger and Preyer[24] have made investigations regarding the itching-reflex (_Kitzelreflexe_), and although in many respects their results are divergent, yet one point is clearly established by both, namely, that within a few months after birth a distinct itching-reflex is in operation, inasmuch as the child endeavours to scratch itching areas. Thus, by itching of the genital organs, a child is readily led to practise masturbation; and this is not necessarily effected by the hands, but sometimes by the feet, or by rubbing the thighs against one another, this last being generally done when the child is in the sitting posture. When erections occur in the child, we cannot always trace them to external stimuli, for in many cases they are due to stimuli of other kinds. Erection may, in fact, result from internal stimuli, connected with the development of the genital organs, and more especially that of the testicles. Moreover, such developmental stimuli may induce the child to manipulate the genital organs, and thus give rise to masturbation, without in the first instance causing erection. It appears that such stimuli leading to the practice of masturbation occur, during the first years of childhood, chiefly, if not exclusively, in children with morbid hereditary predisposition.