"jZhI^VmSHS?'] Regeneration of the Sjnnal Cord. 239 



intermediate position between the regenerative process of cerebral 

 matter, and that of the nerves. However, if we consider the general 

 configuration of the cord, and the clearly-marked difference between 

 the forms of the two medullary ends during the early period of the 

 reparative process; if we remember that the imtial phenomena, 

 which have revealed the existence of a nervous union, were almost 

 exclusively phenomena of conductibihty ; if, finally, we consider that 

 the white portion of the cord may, up to a certain point, be com- 

 pared to bundles of roots, we shall be disposed to group the regene- 

 ration of the cord with the reproduction of the nerves, rather than 

 with that of the cerebral hemispheres. The hrain would then fidfil, 

 with respect to the cord (so far as the regeneration of the latter is 

 concerned), the same function that the cord fulfils with resjpect to 

 the racliidian nerves. 



We have yet to explain certain pecuHarities noted in our observ- 

 ations. 



1. The difference proved to exist between the date of the return 

 of voluntary motility, and that of conscient sensibility. 



The theory of troijhic centres may give us the key to this fact. 

 The spinal ganglia are, in fact, looked upon as the nutritive centres 

 of the sensitive rachidian fibres, while the cord is the common nutri- 

 tive centre of the anterior roots. It is extremely probable that the 

 same holds good with regard to the two kinds of intra-medullary 

 fibres which constitute in the interior of the spinal axis the direct 

 or indirect prolongation of the. roots. Now, in every transverse 

 section of the cord, affecting at the same time a sensitive root be- 

 tween its meduUary insertion and its spinal ganglion, the fibres that 

 remain attached to the cord, and those also which continue the root 

 into the cephalic segment of the cord, will cease to be in communi- 

 cation with their trophic centre (the spinal ganglion), whilst, on the 

 contrary, the corresponding motor fibres will not have been sepa- 

 rated from their centre (the grey matter of the cord). We can now 

 understand that the intra-medullary motor fibres degenerate less 

 and are repaired more quickly than then- neighbours ; which explains 

 the earlier return of voluntary motility. 



2. The presence in a tissue invaded by a neo-formative process, 

 of cells laden with pigment and frajjpees cVinertie. 



This fact is not surprising, seeing that nervous cells present, 

 even in the physiological condition, a great tendency to pigmenta- 

 tion, and that besides, a necro-biological action is almost always 

 found combined with the neo-formative process. In a process 

 closely related to this — the regeneration of the nerves — the two 

 phenomena are constantly observed progressing simultaneously. 



3. The predominance of the cellular elejuents in newly-formed 

 tissue, and the maturity of those elements compared with the em- 

 bryonic state of the fibres. 



This circumstance may be accounted for by comparing the new 



