DEVELOPMENT OF FIBRES. 403 



It would lead us too far to follow tlie many ap- 

 plications of these facts to the vexed questions of 

 nervous histology and physiology. The hotly-debated 

 controversy respecting fibres as prolongations from 

 ganglionic cells, for example, seems to me decisively 

 settled by the fact that, in the Molluscs, we have 

 cells without fibres, and by the fact that, in the recently- 

 born dog, we have fibres which have not yet effected a 

 junction with the cells. Again, when Funke, review- 

 ing the controversy respecting the existence of gangli- 

 onic cells destitute of processes, says that, " from all we 

 know of the functions of the nerve-elements and the 

 laws of conduction in them, an isolated apolar nerve- 

 cell appears as an anomaly (Uiiding) to which we 

 can in nowise assign a physiological purpose,"* he is 

 assuming that without fibres terminating in cells no 

 nervous transmission can take place — an assumption 

 flatly contradicted by the facts we have just been 

 considering. 



What we metaphorically call " nervous conduction " 

 takes place not only in the absence of fibres, but also 

 in the absence of any nerves whatever. There is no- 

 thing like the sharp angle of a paradox to prick the 

 reader's attention ; and here is one in all seriousness 



in the second class to be considered as fibres, he is certainly wrong. 

 It should be noted that what are called fibres in the vertebrate nerve- 

 tissue are really tubules with fluid contents. This fact was discovered 

 by Leeuwenhoek, who describes them as vessels (see his Select Works, 

 ii. 303), a discovery often erroneously attributed to Ehrenberg, to 

 whom the credit is given in Mr Hogg's popular work, The Microscope, 

 3d edition, p 525. 

 * FuNKE, P^sto^ie, p. 419. 



