DR. HUGHLINGS JACKSON. DR. FERRIER. 323 



monkeys, has been able to deduce some very interesting 

 conclusions, which will shortly be published in detail.* 



Dr. Hughlings Jackson has long been engaged upon the 

 same line of enquiry, but from the clinical side, and has 



* Dr. Ferrier's conclusions are as follows : 



" I. The anterior portions of the cerebral hemispheres are the chief 

 centres of voluntary motion and the active outward manifestation of in- 

 telligence. 



" 2. The individual convolutions are separate and distinct centres ; 

 and in certain definite groups of convolutions (to some extent indicated 

 by the researches of Fritsch and Hitzig), and in corresponding regions 

 of non-convoluted brains, are localised the centres for the various move- 

 ments of the eyelids, the face, the mouth and tongue, the ear, the neck, 

 the hand, foot, and tail. Striking differences corresponding with the 

 habits of the animal are to be found in the differentiation of the centres. 

 Thus the centres for the tail in dogs, the paw in cats, and the lips and 

 mouth in rabbits, are highly differentiated and pronounced. 



" 3. The action of the hemisphere is in general crossed ; but certain 

 movements of the mouth, tongue, and neck are bilaterally co-ordinated 

 from each cerebral hemisphere. 



"4. The proximate causes of the different epilepsies are, as 

 Dr. Hughlings-Jackson supposes, ' discharging lesions of the different 

 centres in the cerebral hemispheres.' The affection may be limited 

 artificially to one muscle or group of muscles, or may be made to in- 

 volve all the muscles presented in the cerebral hemispheres, with foa'm- 

 ing at the mouth, biting of the tongue, and loss of consciousness. When 

 induced artificially in animals, the affection as a rule first invades the 

 muscles most in voluntary use, in striking harmony with the clinical 

 observations of Dr. Hughlings Jackson. 



"5. Chorea is of the same nature as epilepsy, dependent on mo- 

 mentary and successive discharging lesions of the individual cerebral 

 centres. In this respect Dr. Hughlings Jackson's views are again ex- 

 perimentally confirmed. 



" 6, The corpora striata have crossed action and are centres for the 

 muscles of the opposite side of the body. Powerful irritation of one 

 causes rigid pleurosthotonus, the flexors predominating over the ex- 

 tensors. 



" 7. The optic thalamus, fornix, hippocampus major, and convolu- 



V 2 



