In some cases of mental torticollis, the attitude assumed may be considered as a stereotyped act. Martin has recorded an example of torticollis in relation to melancholia. Another of his patients suffered from rotation of the head to the left, a position which could easily be rectified by asking the man to make the sign of the cross. The moment he put his finger on his forehead the displacement of the head was corrected. If, however, he were requested to look straight in front of him, he remained incapable of altering the vicious attitude, the reason he advanced being that he could no longer see the sun. One cannot but be struck with the remarkable analogies to the cases given by Cohen. And it is worth remembering further, that sometimes mental torticollis degenerates into actual dementia. TICS AND SPASMS Nothing is more arduous, at first sight, than the differentiation of a tic from a spasm, the similarity of their external forms being a fertile source of confusion. Yet the establishment of a correct diagnosis is of prime importance, since in their case prognosis and treatment alike are diametrically opposed. Tic is a psychical affection capable of being cured, if one can will to cure it: at the worst we may fail, but there is no idea that it is indicative of a grave organic lesion prejudicial to life. A spasm, on the contrary, though it appear in almost identical garb, is excited by a material lesion on which depends the degree of its gravity. The focus of disease may disappear, no doubt, but it is only too likely to persist and to occasion other disorders. Hence the desirability of making sure of one's diagnosis--a proceeding not necessarily of insuperable difficulty. If we apply the principles of diagnosis enunciated by Brissaud, to which our attention has already been directed, we shall not find the task beyond our powers. Let us take a concrete instance. Here is a cabman, forty-nine years of age, the left half of whose face is the seat of convulsive twitches. These commenced eighteen months ago by brief insignificant contractions of the left orbicularis palpebrarum, which have gradually spread to the whole of the muscular domain supplied by the left facial nerve. Their momentariness and rapidity, their apparent independence of extraneous stimuli, their indifference to treatment and resemblance to the twitches produced by electrical excitation, their occurrence in sleep, the fact of voluntary effort, of attention or distraction, serving so little to modify their range and intensity--all make clear the spasmodic nature of the condition.