Echokinesia may be considered a motor disturbance analogous and akin to tic, but distinguished by the fact that it occurs exclusively during the performance, and as the reproduction, of some movement executed by another. It is true, of course, a genuine tic may be a reminiscence of some gesticulation, but it is quite independent of time and place. A similar difference exists between echolalia--the habit of repeating another's sounds or words at the moment of their ejaculation--and tics of phonation or of language; the latter are always ill-timed and inappropriate, though they may have had their origin in acts of imitation. It has become classical to draw a comparison between these echokinesic phenomena and the observations of O'Brien apropos of _latah_ among the Malays. A sailor on board a boat will pick up a piece of wood and proceed to rock it as if it were a child, whereupon a _latah_ standing alongside commences to rock the infant he holds in his arms. The sailor then throws the piece of wood on to the deck, and the _latah_ promptly follows suit with the baby (Guinon). This is echokinesia carried to an extreme, revealing a complete absence of inhibition from the higher psychical functions. Prominent among influences calculated to facilitate the evolution of tics is the patient's environment, more particularly where children are concerned. The parents are often disposed to be deplorably "fond." Their ignorance or their thoughtlessness permits the installation of obnoxious habits and fosters their growth into tics. Any endeavour after suppression usually serves to expose the inadequacy of the family authority to exercise control and compel obedience. For the watchful discipline that should curb all such childish tricks and caprices is unfortunately substituted a disastrous indulgence that only stimulates the development of these embryonic tics. It should not be forgotten, moreover, that the mental instability of the fathers is visited upon the children in the guise of a certain aptitude for psychical anomalies. The accompanying case supplies conclusive evidence of the mischief wrought by weakminded parents, and of the calamitous results of hereditary predisposition and bad example combined. S.'s mother is a lady of over fifty, who spends her leisure hours in writing novels, and who suffers from different varieties of phobia. In the first place, she has an absurd fear of cats and dogs. When she goes out, a maid follows at several yards' distance to prevent the approach of any dog from the rear; and if she is driving, the same precautions are observed. Her dread of chest complaints is equally extravagant. A cold is her bugbear, a draught her _bête noire_. In the intervals of her literary labour she occupies herself with seeing that all doors and windows are properly shut. The room temperature is maintained at 68° F. at least.