376 SEA-SIDE STUDIES. 



(Syngnathus) ; none in that of a Dogfish (Acanthias) of 

 about a foot and a half long. It would be perilous to assert 

 that there were absolutely no fibres in the brains of these 

 animals, but if there were any, they must have been exceed- 

 ingly rare, as I could not find one : and theory requires that 

 there should be one or more for every cell.* 



These facts are important as well as novel, and force us to 

 the conclusion that fibres are not necessary to the conduc- 

 tion of nerve-force, although they may be special organs of 

 conduction, wherever they exist. The point to which the 

 reader's attention is required is that nerve-force can be trans- 

 mitted — that neiTC-actions can take place — in the absence 

 of primitive fibres. This might have been concluded from 

 the structure of the olfactory nerve alone, wliich, by a re- 

 markable peculiarity, shows a break in the continuity of its 

 fibres, the intervening space being occupied with granules 

 only. This is the case in all animals.-}- And I find a still 

 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 conveyed by a fibre to a cell, 



* Plate VII., fig. 2, gives a hypothetical diagram of the relation of fibres and 

 colls in the spinal chord and brain, according to the latest ideas. Whatever 

 truth it may have in reference to the higher vertebi-ates, it is ceitainly not 

 appliciible to those fish and reptiles I have examined. 



+ See the description of the olfactorius in Leydio, op. cit. 



X The necessity for caution, both in extending our observations and in mak- 

 ing 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 uninterrupted in 



