We must not mistake the stolid for the hypokinetic. There was a classmate of mine in the medical school, a large, quiet fellow, D. M., who got by everything, as the boys said, by the skin of his teeth. He worked without enthusiasm or zeal, studied infrequently and managed to pass along to his second year, at about the bottom of the class. In that year we took up bacteriology, the "bug-bear" as one punster put it, of the school. Just what it was about the subject that aroused D. M. I never knew, but a remarkable transformation took place. The man changed over, studied hard, read outside literature and actually asked for the privilege of working in the laboratory Sundays and holidays so that he might learn more. When this was known to the rest of the class, there were bets placed that he would not "last," but quite to the surprise of everybody D. M. gained in momentum as he went along. As a matter of fact, his interest on the subject grew, and he is now a bacteriologist of good standing. In fact, his lack of interest in other matters has helped him, since he has no distracting tastes or pleasures. Thus there are persons of specialized interest and energy, and it may well be that there is for most of the hypokinetic a line of work that would act to energize them. The problem, therefore, in each case is to find the latent ability and interest and to regard no case as really hopeless. I say this despite the fact that I believe some cases are hopeless. The pessimistic attitude on the part of parent or teacher kills effort; the optimistic attitude fosters energetic effort. 6. The irritable hypokinetic. Irritability[1] of a pathological type as a phase of lowered energy is well known to every physiologist and in the practical everyday world is seen in the tired and sick. There are people who from the very start of life show lowered endurance, who respond to certain stimuli in an excessive manner and are easily exhausted. This type the neurologist calls the congenital neurasthenic, and it may be we are dealing here with some defect in the elimination of fatigue products. This, however, is only a guess, and the disease factor, if there is any, is entirely unknown. I do not pretend that the person I am to describe is entirely representative of this group. Indeed, no dozen cases would show all the symptoms and peculiarities of the irritable hypokinetic group. [1] One must take care not to mistake the irritability which is the characteristic of all living tissue for the irritability here considered.