contamination in the course of such a prosecution. When we take a comprehensive view of the harm that may be done to children by sexual offences committed against them and by the consequent legal proceedings, we shall find, in my opinion, that from the legal proceedings arises a notable proportion of the injury. The examination of the mental condition of the child-depraver is a matter of the utmost importance. In cases in which we find that the offender is suffering from some pronounced mental disorder, such as progressive paralysis (paralytic dementia), senile dementia, or an epileptic disturbance of consciousness, there can be no doubt as to the existence of irresponsibility; but it must never be forgotten that in the early course of such diseases, these sexual perversions often make their appearance at a time when no other definite signs of the brain disease have as yet appeared, and that for this reason the conviction of innocent persons--old men, for instance--on account of sexual offences against children, often occurs. Kirn,[125] who in the Freiburg prison had under observation six old men at ages from sixty-eight to eighty-one, all convicted for sexual offences against little girls, states that in all of these there were intellectual defects, and in several of them pronounced symptoms of senile dementia. The psychiatric expert must examine all such cases with the utmost care. We may also express a wish that judges were not inclined to regard themselves as experts in this field, of which, as a rule, they have no expert knowledge whatever.