lymph or blood-stream, and give rise to the development of the secondary sexual characters. Thus, the effects of castration are due, on this theory, not to the absence of the formation of spermatozoa, but to the absence of the products of the interstitial glands. French investigators consider that the assumption that such an interstitial gland exists is justified by the results of experimental work. Whichever theory we accept, the chemical or the nervous, both theories harmonise equally with the fact that in boys, before the formation of spermatozoa begins, processes occur in the testicles which powerfully influence the organism. Thus, we learn also from a study of the results of castration how active is the sexual life even in childhood, since thus early in life influences proceed from the reproductive glands whereby the development of the secondary sexual characters is markedly affected. The principal sexual processes occurring in childhood have now been described. Although we have been forced to admit the fact that in the child sexual processes are much more extensive than has commonly been believed, we must, on the other hand, guard ourselves against the exaggerations of those who interpret everything in sexual terms. In the chapter on diagnosis it will be necessary to refer to these exaggerations once again. As a rule, of course, the manifestations of the sexual life of the child increase from year to year, although not always by continuous gradations. Thus, in consequence of misdirection, sexual manifestations may arise in the child, and then, if these evil communications are cut off, such manifestations may cease. But, altogether apart from deliberate seduction, we may observe periods of more rapid and periods of less rapid sexual development, the causes of which may remain obscure. Individual cases vary to such an extent, that it is impossible to lay down a rule to which there are no exceptions. This applies equally to both components of the sexual impulse, to the phenomena of detumescence as well as to those of contrectation.