3 22 



NEW EXPERIMENTS. 



act of thinking. These remarkable bodies constitute an 

 essential part of the apparatus which is influenced by the 

 mental bioplasts. 



Perhaps the relation borne by the little bioplasts 

 to the nerve mechanism may be roughly, but not inaptly, 

 compared with that which subsists between the intelligent 

 workman and the highly complex machinery which he 

 directs and controls, stops and sets going. He would be 

 useless without the machinery, but the latter could not 

 work to any advantage except under the superintendence of 

 an intelligent director. 



Experiments have lately been made with the view of 

 determining the influence of different parts of the convolu- 

 tions of the grey matter of the brain upon combined mus- 

 cular movements, and of ascertaining whether the existence 

 of centres connected with the performance of special acts 

 could be established. It has been proved that irritation of 

 definite areas of the brain surface of an animal under the 

 influence of an anaesthetic is immediately followed by the 

 action of certain groups of muscles, in most cases on the 

 opposite side of the body. By carefully noticing the par- 

 ticular movements, at least one important action of the part 

 irritated will have been determined, though it does not 

 necessarily follow that the part affected ought to be 

 regarded as a special centre of action. 



Fritsch and Hitzig (Reichert and Du Bois Raymond's 

 Archiv., 1870), used the galvanic current, and found that 

 the combined action of muscles of the leg, arm, neck or 

 face could be produced by subjecting certain definite points 

 of the surface to irritation. More recently Dr. Ferrier has 

 taken up the same enquiry, and, from experiments upon 



