660 Sir James Crickton-Browne [May 27, 



curtain of flickering liglit over its whole surface. And think of the 

 brain, again, in times of intense conscious elevation, of concentrated 

 attention or agitated feeling, and picture it as sending forth from 

 its luminous arch of common consciousness long brilliant rays of 

 psychical energy, that shoot towards the zenith, now here, now there, 

 now east, now w^est, green, purjDle, or violet, according to the emotive 

 complexion of the moment. 



But whatever image of the brain in its active and quiescent states 

 we may form, the important point to bear in mind now is that some 

 of its special activities — long rays of function — may be evoked by 

 thai electrical stimulation of its surface which Mosso has shown to 

 cause a rise of temperature there. It was the determination of this 

 fact by Fritsch and Hitzig that was the starting point of all the 

 discoveries in cerebral physiology since made. They showed that 

 the surface of the brain, which all previous experimenters had found 

 to yield absolutely no response to any kind of stimulation, mechanical 

 or chemical, that could be applied to it, is excitable to electricity. 

 Before their time, brains of living animals (exposed by removal under 

 chloroform of the skin, skull, and membranes) had been subjected to 

 stimulation, by light, heat, pressure, acid, alkalies, pricking, and 

 burning, and had remained dead and inert, insensible and motionless. 

 But under the inspiration of their genius, brains of living animals, 

 the moment that their surface was touched by the electrodes con- 

 nected with a battery, sprang as it were into life and moved respon- 

 sive to every appeal made to them. 



One spot on the surface (and let us suppose it is a monkey's brain 

 that is under observation) is touched by the electrodes, and the knee 

 of the opposite side is bowed ; the electrodes are removed, and it is 

 straightened. An adjoining spot is touched and the ankle is twisted ; 

 the electrodes are raised, and it is straightened. Another spot is 

 touched and the shoulder is raised, another and the elbow is flexed, 

 another and the wrist, and so on, through all the movements of leg, 

 foot, arm, hand, fingers, face, neck, trunk. It is exactly like playing 

 the piano : a key is depressed and a definite note follows ; a spot is 

 touched and a definite movement follows. And every time that the 

 same spot is touched, the same movement follows, while an adjacent 

 spot gives an entirely different movement with the same unerring 

 regularity. No puppet responds more accurately to the twitching of 

 the strings attached to it than do the body and limbs of a deeply 

 unconscious monkey to the touches of the electrodes of the experi- 

 menter, who can make it perform any movement you may suggest. 

 Numerous elaborate and careful experiments have made it certain 

 that all the movements of the body are localised or have their central 

 springs of action in this middle region of the brain, and that they are 

 localised there in a definite order, movements of the lower limbs being 

 uppermost, those of the upper limbs next in order downwards, and 

 those of the face lower still. 



But it may be objected that these movements have been localised 



