ARE FIBRES NECESSARY FOR CONDUCTION? 395 



greater break in the sympathetic nerve of the new-born 

 puppy. As the trunk is about to join the ganglion, 

 the fibres disappear, and give place to granules ; nor 

 do fibres appear in the ganglion at all* Now, as 

 theory requires every nervous impression to be con- 

 veyed by a fibre to a cell and by a fibre from 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 indubitably 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 authori- 

 tative physiologists ; it will be useful, therefore, to show 

 that I was not combating an exploded error. In Eng- 

 land 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-conductor, or its continuity is in- 

 terrupted, and so its power of conduction is rendered, 



* The necessity for caution, both in extending our observations and 

 in making them public, is illustrated by the fact, that since the above 

 was written, I have seen one sympathetic ganglion in which the fibres 

 did penetrate ; and it is worth mentioning that I found the continuity 

 of the fibres unintemipted in all the sympathetic nerves of a new-bom 

 kitten. Let me add that, except in the case of the Slug {Limax), all 

 the facts stated in the text are founded on multiplied observations ; 

 the magnifying powers used being 350 — 750 linear, with one of Smith 

 and Beck's excellent Microscopes. 



