NERVE FIBRES OF CONVOLUTIONS. 321 



nerves in many delicate nerve organs, and there is good 

 reason for thinking they are of all parts of the structure 

 certainly not the least essential. In a work published by 

 me last year, " Life Theories and Religious Thought," I 

 have described the minute bioplasts referred to, and have 

 given figures to illustrate the arrangement. I believe that 

 the bioplasts referred to are directly concerned in mental 

 action. Movement affecting the matter of many thousands 

 of these minute bioplasts, probably at the same moment, 

 is required for the initiation of the simplest idea. But not 

 the slightest movement could occur in any part of one of 

 them, without many fine nerve fibres connected perhaps 

 with widely distant points being affected however slightly, 

 the particular fibres and the number of them influenced 

 varying of course in every case. 



The number of the nerve fibres, like that of the bio- 

 plasts, is altogether beyond calculation. A portion of grey 

 matter upon the surface of a convolution, not larger than 

 the head of a very small pin, will contain portions of many 

 thousands of nerve fibres, the distal ramifications of which 

 may be in very distant and different- parts of the body. 

 These nerves may, however, only indirectly influence distant 

 parts through the intervention of other nerve fibres, and 

 some of them may be concerned in directing the associated 

 movements of certain fibres of several different muscles. 



I believe the caudate nerve-cells, which form such 

 prominent objects, and which are very numerous in the 

 grey matter of the brain of man and mammalian animals, 

 ought not to be regarded as the sources of mental nervous 

 influence, although doubtless they are very intimately con- 

 cerned in, and indeed may be absolutely necessary to the 



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