174 Journal of Comparative Neurology. 



that the nenrite discharges the impulse that has thus been 

 brought to the cell ; or in other words that the direction of the 

 impulse with relation to the cell is always cellipctal through the 

 dendrites and cellifugal through the newites. Cajal and Van 

 Gehuchten were the first to propose this theory, but unless we 

 recognize the peripheral branch given off from the unipolar cells 

 of the spinal ganglia as a dendrite, we have an apparent excep- 

 tion to what has just been stated. Van Gehuchten (1893, Le 

 Systeme nerveux de 1' Homme) represents the peripheral branch 

 from the ganglion cell much coarser than the central branch. 

 Sclavunos has confirmed this appearance in his work on 

 the Salamander, and the morphological distinction between 

 these two processes is further strengthened by the fact that the 

 peripheral process has been found to divide into two in the gan- 

 glion and continue out toward the periphery. On this basis 

 then there are no adendritic cells. 



It is doubtful if a classification of nerve elements adequate 

 for all needs and conditions will ever be devised. Golgi's divis- 

 ion of nerve cells into those of the first and second order is 

 well known. Schafer's classification has already been men- 

 tioned. Baker (1893, N. Y. Med. Journal) proposes the term 

 (Bsthesioblasts to replace ganglioblasts used by Lenhossek, for the 

 cells of the spinal ganglia. Such distinctions are convenient 

 and useful and enable us to get a firmer grasp upon the various 

 complexities of the nervous system, and to hold fast those 

 which we already have. 



For the equivalent of a nerve unit including the nerve cell 

 with all its processes to the uttermost filament, the term neuro- 

 cyte is suggested. It has not been possible to trace the word to 

 its originator. It is in use in the French language and is in- 

 cluded in the dictionary of the New Sydenham Society and 

 Gould's New Medical Dictionary with the simple definition ; a 

 nerve cell. It correlates very well with leucocyte and indeed is 

 somewhat analogous in form if we may consider the appendages 

 of the nerve cell as comparable to the pseudopodia of a white 

 blood corpuscle long drawn pwX. and fixed in position. As a 



