In the first place, it is rather an uncommon functional adaptation of the facial muscles to utilise them in an attempt to disembarrass oneself of disagreeable sensations; and in the second it is no less uncommon for the sufferer from tic to be unable to restrain his muscles even momentarily, as our patient appears to be. The actual time of onset of the movements is significant enough, but of supreme importance is the fact of their supervention in an area previously the seat of paralysis. To our mind this is more than a coincidence; from the history supplied by the patient it is plain that the paralysis was peripheral and that the lesion involved the facial trunk somewhere in its intracranial course after its emergence from the side of the pons. Thirteen years later, convulsive movements appear in the same domain. Taking all the circumstances into consideration, we think the hypothesis tenable that the trigeminal is implicated in the pathogeny of the spasm, although the condition is not strictly comparable to the classic tic douloureux. The exact nature of the lesion is more difficult to determine. A review of the details of the facial palsy suggests its vascular origin, to which theory the headache, nausea, and photophobia of succeeding days and months--indicating, as they do, a circulatory disturbance in the basilar region--lend support. With the gradual restoration of vascular equilibrium the migrainous attacks lessened in frequency and severity, though the facial trunk remained compressed, till the spasm appeared, no less suddenly than had the paralysis. It is feasible that the former, too, is the derivative of a minute hæmorrhage irritating either the centrifugal or the centripetal arm of the facial reflex arc, probably the latter, which would explain the paræsthesiæ. The possibility of this explanation being accurate is confirmed by a case reported by Schültz, where facial spasm of ten years' duration was shown at the autopsy to have been caused by an aneurism of the left vertebral artery impinging on the facial nerve in the neighbourhood of the basilar trunk. The arguments, therefore, which plead in favour of the spasmodic nature of the condition seem to us so cogent that the hypothesis of tic must be rejected. We ought not to forget, on the other hand, that a spasm, of whatsoever origin, may be transformed into a tic by the perpetuation of a morbid habit. Let us take a second case, no less instructive than the preceding.