Under the heading of “katatonia” are included certain peculiar states of stupor and excitement, which tend to alternate irregularly with one another. Thestuporose phase is characterised by increased muscular tension, or in some instances catalepsy, together with negativism, mutism, refusal of food, contrary acts, or not infrequently an increased suggestibility, as shown by echolalia or echopraxia. The prominent features of katatonic excitement are increased psycho-motor activity, attitudinizing, stereotyped movements and phrases, verbigeration, and senseless impulses. Various forms of convulsive attacks are motor phenomena which frequently occur during the course of the psychosis.