A tic of writing, however, is of a totally different nature. He who, without pen or pencil, is constrained by irrepressible impulse to go through the movements of writing with his fingers, convulsively, impetuously; and he who, without rhyme or reason, feverishly traces characters utterly at variance with the ideas he would express, are alike subjects of a writing tic. Of the former, we know no characteristic example, while in the latter case the study of the phenomenon would lead us too far into the realm of automatic writing and graphic impulsions. We must content ourselves with recalling its occurrence in an undeveloped form in the case of O. Among those who are affected with tics, disorders of writing are very infrequent, even where the tic's exhibition is displayed in the upper extremities. One of the distinctive features of tics, in fact, is the brevity of the interruption they cause in the performance of any voluntary act on the part of the patient. Tics of arm or hand effect but little modification of his writing. He is rarely taken aback by his tic's convulsive demonstration. He can permit the co-existence, on a perfect understanding, of two automatic acts, normal and abnormal, writing and tic. One of Guinon's patients was wont to proceed in the following way: if asked to write, he would lean on the table, pick up his pen, and just ai it was about to touch the paper, make several little movements of circumduction with his right hand, as a child does. Thereafter, he would sometimes pass on at once to trace the letters; at other times he would have to grind his teeth, contort the right half of his face, put out his tongue, pucker his nose, or dip his pen spasmodically into the ink ten consecutive times--ejaculating ahem! ahem! the while--before being able to commence. He would often cease altogether, to make one or two grimaces, or to wave his hand about. As far as the actual writing was concerned, its distinctness and evenness were no less praiseworthy than its style and content, and though a glance at his gesticulations led one to expect blots and irregularities in his manuscript, he conducted his task with assurance and correctness. Of course, if the tic, whatever it be, exceed a certain limit of frequency and violence, accurate writing may amount almost to a physical impossibility, in which case the patient usually discontinues, although if called on to exercise his will he can always pen a few words and even a few lines. However this may be, the spots and scrawls and zigzags and shaky cramped characters we associate with such organic affections as tabes, Friedreich's disease, paralysis agitans, etc., are wholly exceptional in the case of tic.