These five cases will have to suffice for the present. They were given in full in spite of the fact that we shall leave out of our present considerations the history of the cases and certain of the stages, and confine ourselves to that stage of each case which is best qualified to give us a good general survey of the essential features of the stupor reaction. These phases are: stage 1 of Case 1, lasting five months; stage 3 of Case 2, lasting one year; stage 2 of Case 3, lasting two years; stage 1 of Case 4, lasting three months; stage 1 of Case 5, lasting four months. We gather from these descriptions that the essentials of the stupor reaction are (1) more or less marked interference with activity, often to the point of complete cessation of spontaneous and reactive motions and speech; (2) interference with the intellectual processes; (3) affectlessness; (4) negativism. _Inactivity:_ There is a complete cessation or more or less marked diminution of all spontaneous or reactive movements. This includes such voluntary muscle reflexes as contain a psychic component. For instance, there is, often, an interference with swallowing (letting saliva collect and drooling), winking, and even with the inhibitory processes used in holding urine and feces (soiling and wetting). Often there is no reaction to pin pricks or feinting motions. The inactivity also often interferes with the taking of food so that spoon-feeding or tube-feeding has to be resorted to. The patient may keep his eyes covered or stare vacantly, the face often presenting a remarkably immobile wooden, or stolid, expression. Complete mutism is the rule. When activity is not totally interfered with, those movements which are present may be slow. The patient may have to be pushed around and be able to take a few steps, but soon relapses. More often they are of normal rapidity. Speech then may also be slow and low, but usually shows no change except for the fact that it is diminished in amount. Sometimes awkward positions are assumed and retained, and there may be catalepsy. _Negativism:_ A common symptom is perverse resistiveness. It may consist in a marked stiffening of the body which is assumed spontaneously or appears only when attempts at interference are made, or there may be a more active turning away or even a direct warding off, sometimes with scowling or anger or even swearing and striking. Retention of urine, which is seen at times, should, perhaps, be mentioned here. Now and then we find that a patient is put on the toilet and cannot be induced to urinate or defecate, while soiling and wetting occur at once on returning to bed.