His earliest tics--simple facial grimaces and movements of the head--made their appearance when he was eleven years old; notwithstanding, his recollection of their mode of onset is very exact. I have always been conscious of a predilection for imitation. A curious gesture or bizarre attitude affected by any one was the immediate signal for an attempt on my part at its reproduction, and is still. Similarly with words or phrases, pronunciation or intonation, I was quick to mimic any peculiarity. When I was thirteen years old I remember seeing a man with a droll grimace of eyes and mouth, and from that moment I gave myself no respite until I could imitate it accurately. The rehearsals were not prolonged, as a matter of fact, and the upshot was that for several months I kept repeating the old gentleman's grimace involuntarily. I had, in short, begun to tic. In my fifteenth year I was at school with two boys whose hair was rather long, and who had acquired the habit of tossing it back by an abrupt shake of the head. It is true I cannot recollect endeavouring to ape this, but in any case it was at the same time that I found myself exhibiting an identical gesture, and I have little doubt it is the source of one of the tics from which I suffer at present. I enlisted at the commencement of hostilities in 1870, and had already begun my military instruction, when a personal review of the company was made by a new colonel. As he passed he came to a sudden halt before me, and proceeded to harangue me on my far from military bearing; but his invective had no other effect than to aggravate my facial contortions, and the affair might have proved serious enough for me had not my captain come to the rescue and explained the involuntary nature of the spasms. The colonel, however, would have none of them and after a fortnight's sojourn in hospital I was discharged for "choreic movements of the face." O.'s tics were at the first confined to the eyes and lips, but others were not long in appearing. He happened to be out one day for a walk with his sister during a snowstorm, and a flake entering his nostril made him sneeze and sniff half a dozen times. Long after the snow had ceased falling and the tickling sensation had vanished he repeated the performance, till it passed into a sniffing tic that continued for some months. His sister thoughtlessly set herself to mimic him, and speedily evolved an identical tic, which still persists.