less marked immediately after the operation than they are half an hour later.[74] This would be impossible were they due to the subtraction of the organs which normally carried them on. Moreover the entire drift of recent physiological and pathological speculation is towards enthroning inhibition as an ever-present and indispensable condition of orderly activity. We shall see how great is its importance, in the chapter on the Will. Mr. Charles Mercier considers that no muscular contraction, once begun, would ever stop without it, short of exhaustion of the system;[75] and Brown-Séquard has for years been accumulating examples to show how far its influence extends.[76] Under these circumstances it seems as if error might more probably lie in curtailing its sphere too much than in stretching it too far as an explanation of the phenomena following cortical lesion.[77] On the other hand, if we admit _no_ re-education of centres, we not only fly in the face of an _a priori_ probability, but we find ourselves compelled by facts to suppose an almost incredible number of functions natively lodged in the centres below the _thalami_ or even in those below the _corpora quadrigemina_. I will consider the _a priori_ objection after first taking a look at the facts which I have in mind. They confront us the moment we ask ourselves just _which are the parts which perform the functions abolished by an operation after sufficient time has elapsed for restoration to occur?_ The first observers thought that they must be the _corresponding parts of the opposite or intact hemisphere_. But as long ago as 1875 Carville and Duret tested this by cutting out the fore-leg-centre on one side, in a dog, and then, after waiting till restitution had occurred, cutting it out on the opposite side as well. Goltz and others have done the same thing.[78] If the opposite side were really the seat of the restored function, the original palsy should have appeared again and been permanent. But it did not appear at all; there appeared only a palsy of the hitherto unaffected side. The next supposition is that _the parts surrounding the cut-out region_ learn vicariously to perform its duties. But here, again, experiment seems to upset the hypothesis, so far as the motor zone goes at least; for we may wait till motility has returned in the affected limb, and then both irritate the cortex surrounding the wound without exciting the limb to movement, and ablate it, without bringing back the vanished palsy.[79] It would accordingly seem that _the cerebral centres below the cortex_ must be the seat of the regained activities. But Goltz destroyed a dog's entire left hemisphere, together with the _corpus striatum_ and the _thalamus_ on that side, and kept him alive until a surprisingly small amount of motor and tactile disturbance remained.[80] These centres cannot here have accounted for the restitution. He has even, as it would