in entertaining the idea of incipient tabes. Even if the existence of other signs had corroborated this diagnosis, the incontestable genuineness of O.'s tics would have remained, so that the attempt to correlate the derangement of the reflexes with the existence of tics is somewhat questionable. We have enjoyed the co-operation of M. Babinski in the examination of one of our patients, L., in whom we were able to determine a definite and symmetrical exaggeration of the patellar reflexes, a slight increase in the right triceps jerk, and, in making the subject rise from a prone to a sitting position with the arms folded, a very minor degree of flexion of the thigh on the trunk. The first of these symptoms is of no pathognomonic value, and while the others no doubt are characteristic of organic disease, their development in this instance is too imperfect to warrant the deduction of pyramidal involvement. For the last ten years L.'s motor control has been very defective. The muscular activity of the right half of his body takes the form of irregular contractions, badly timed and inaccurate in range; in spite of the absence of pain, the timidity with which they are executed hinders their ever attaining a normal amplitude; and at the same time his inability to appreciate the direction and intensity of the motor reaction, the outcome of excessive muscular vigilance, illustrates a certain loss of the sense of position of his limbs. The existence of an actual irritative lesion is therefore problematical, and it is scarcely conceivable that organic mischief of ten years' duration could have produced these clinical symptoms without creating graver disturbance of the reflexes, or effecting changes of a trophic nature in muscular and other tissues. From the pathogenic and diagnostic point of view, the detection of conspicuous and persistent alterations in the reflexes is of deep significance. It is an important factor in the differentiation between tic and spasm. Sometimes the task is unusually arduous, as when the unilateral distribution of the motor troubles recalls the clinical picture of lesions of the pyramidal paths. In L., for instance, the hemichorea and the torticollis were on the right side, and in a case published by Desterac a similar condition obtained, the writers' cramp, hip spasm, and head rotation being all confined to the right. Notwithstanding the fact that this patient had exaggerated knee jerks, ankle clonus, and a double extensor response, an opportunity for examination given to one of us made it clear that the untimely movements and bizarre attitudes were similar to what has been noted in certain cases of tic.