Reviewing a large number of cases of idiocy and imbecility which have come under my observation, I am able to call prominently to mind three cases in which apparent hypertrophy of muscle, combined with motor paralysis, was present. As these occurred to me before Dr. Duchenne, of Bologne, had pointed out their significance, I did not take steps to verify their condition. So marked, however, was the apparent muscular development, that the muscular feebleness puzzled me much. Faradization was tried in one case without any good result.