ARE FIBRES NECESSARY FOR CONDUCTION? 377 



aud by a Gbrefrom the cell, we see at once that the foregoing 

 facts, or any one of them, must strike at the root of such a 

 theory, nervous impressions being indubital )ly transmitted 

 where no fibres exist, and where a solution of continuity exists. 

 Since these observations were first published, I have 

 found more than one professional man disposed to doubt 

 that the theory of conduction is held by authoritative 

 physiologists ; it will be useful, therefore, to show that I 

 was not combating an exploded error. In England Dr Todd 

 certainly holds place in the highest ranks; and in 1856 

 he thus wrote of softened brains : " In all cases the cerebral 

 disease reaches such an extent that the vesicular matter 

 imperfectly generates the nervous force, and the fibrous 

 matter becomes a had conductor of it, or even a non-con- 

 ductor, or its continuity is intern-upted, and so its poiuer of 

 conduction is rendered, in the one case, physiologically, in 

 the other mechanically, impossible."* Can anything be more 

 explicit ? A solution of continuity between fibre and cell 

 is said to render the conduction of nerve-force impossible ; 

 yet I have shown that such a solution is constant in many 

 animals, and is present in the embryonic condition of all 



all the sympathetic nerves of a new-bom kitten. Let mo add that, except in 

 the case of the Slug (Limax), all the facts stated in the text are founded on 

 multiplied observations ; the niagfuifying powers used being 350 — 750 linear, 

 with one of Smith and Beck's excellent Educational Microscopes. 



* Todd : Clinical Lectures on Paralysis, 2d ed., 1856, p. 211. Equally explicit 

 is Gratiolet : A nat. Comp. du Sydemc JVerveux, 1857 ; ii. p. 4. So also KiUKES 

 and Paget, in their Ilandhook of Physiology, p. 364. " All nerve-fibres are 

 mere conductors of impressions." In Segond, Traiti cC Anatomic Genirale, p. 

 Ill, the nei've-fibre is said to manifest a new and chai-acteristic property, that 

 of transmisxihility, as the musale-fibre manifests that of contractibility. Com- 

 pare also FUNKE, Lchrbuch der Phy.nolo(jie. 



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