Eighteen cases or 7.5 per cent. of the 240 cases studied have been epileptics; 16 cases or 6.6 per cent. have hysteria. Both conditions are very important as factors of social instability. The variability of epileptics and the extremes of which they are capable are well known to students of criminology. Many times we find cases suggesting a latent epilepsy among individuals in whose families there are other cases of the same disease. In these cases we see only what appear to be psychic manifestations or great irregularity in tests and behavior. The cases of hysteria are also interesting on account of their extreme suggestibility. It is only necessary to watch the manifestations of this characteristic in an institution, to realize what an important factor suggestibility has been in the outside world in leading to their delinquencies. Mental imagery in such cases is of immense importance. One case of hysteria which we had under observation would while in her attacks of unconsciousness, often repeat (naming a woman who was living a life of prostitution outside), “Mary, I will come to you; I will give up my child; there is nothing else for me in the world and I will come to you and do as you say.” In studying her mental processes, the pictures which had been drawn for her of luxury and gaiety in such a life were continually before her, too strongly contrasted with any reasonable pictures which it was possible for us to conjure up for her. Another important class is that which includes the borderline cases, which have perhaps never been satisfactorily classified. Many of these would be in the group termed by one authority “control defectives.” The term expresses well their explosive natures which may be seen when, without provocation they attack any person who happens to incite their enmity, whether she be officer or other inmate, or when by unreasonableness and loss of temper they bring unruliness and the necessity for discipline into an otherwise peaceful and well-behaved group. Many of these cases come from families in which there are many cases of insanity, and although they themselves show no signs of a definite psychosis, there appears to be much inherited instability. Other cases show the results of a meningitis or an encephalitis which they have had in childhood. Occasionally we see cases in which the instability apparently followed a head injury.