By the month of October, 1900, the latter was at its height, and had reached a state where differentiation of the movements and of their muscular counterparts was attended with no little difficulty. They could be resolved into four principal groups, whereby the shoulder was raised, lowered, advanced, or drawn back, respectively. The first of these presented no unusual feature except that with it the head was commonly inclined to the same side; but the act of depression was rather peculiar, inasmuch as it was achieved by a sudden contraction of the inferior muscles of the scapula, together with the pectoralis, which drew the humeral head downwards, elongated the capsule, and stretched the deltoid fasciculi over it. The space thus left between the separated articular surfaces was partly filled in by the neighbouring ligamentous and muscular structures. Anterior or posterior projection of the shoulder took place at the expense of an actual subluxation, the head of the humerus bulging under the pectoral or the scapular muscles. Each and every movement was accompanied by articular cracking, sometimes so insignificant as scarcely to be pathological, to which, nevertheless, the boy attached extravagant importance and devoted methodical investigation. Ordinary arm movements were, without exception, unimpaired, nor was any bony malformation discoverable. The two shoulders were practically symmetrical, though the upper border of the trapezius on the left side was, if anything, thickened and more prominent than its fellow, and the same applied to the left scapular muscles. Horizontal extension of the left arm revealed a slight tremulousness, quite distinguishable from pathological tremor and from fibrillary twitching, and wholly comparable to what is seen when, by reason of a fracture or otherwise, a limb is for a certain length of time prevented from executing movements of extension. [Beating or striking tics (the patient using his own fist against himself) arise from the attempt to alleviate some insignificant pain or irritation; but tics of this kind are in their turn the exciting cause of local discomfort, and so of fresh tics. In spite of the obviousness of this, it is often difficult to convince the patient that his movements are prior, not consecutive, to the unpleasant sensations.[99]] Finally, tonic tics of the upper extremity find expression in attitudes that vary with the localisation of the contraction. We have already had occasion to observe this, which is an almost constant phenomenon in mental torticollis, in the case of young J., in Madame T., and in N., where, it will be remembered, the all but permanent elevation of the right shoulder seemed traceable to the habit of cutting stuffs with a pair of large scissors. TICS OF THE HANDS--SCRATCHING TICS