106 C. WINKLEK. THE CENTHAL COUESE 



were found within a fortnight after the lesion , and if the myelini- 

 sation-method or Golgi-method confirmed its possibility. 



The second is to suppose, that rootfibres having been stopped 

 by a nucleus, where they find a preliminary end, (it may be indif- 

 ferent whether cells are intercalated between them and the cells 

 from which the secondary system originates, or not) damage the 

 cells of that nucleus, after a longer or shorter lapse of time, and 

 in this way cause a degeneration in the secundary system. 



Or if the often controversed hypothesis of neurons coming into 

 contact with the cells should prove false, if this hypothesis ought 

 to be rejected and replaced by another, teaching an uninterrupted 

 continuity of nervous fibrils, - - it still may be presumed, that dege- 

 nerated fibrils, degenerating through the cells of the nucleus reap- 

 pear in the fibres of the secundary system and cause the degeneration 

 of the fibre as a whole, made visible by Marchi-method. 



In this way may be interpreted the fact, that the longer time 

 has elapsed after the lesion, the greater is the number of degene- 

 rated fibres found in secundary systems, according to the theoretical 

 views of the investigator and his defending the neuron-hypothesis 

 or the hypothesis of the continuity of the nervous fibrils. 



Now this danger of MARCin-method may under circumstances 

 become an advantage. For if, after a long lapse of time rootsection 

 can make visible degenerate fibres in secundary tracts, it may be, 

 that a few degenerate fibres in a denned tract furnish an indication, 

 a presumption that this tract might prove a secundary one. 



Yet, this way may appear dangerous. The longer a degeneration 

 has existed, the more are the chances that the altered my elm 

 (the black globules) is spread and dislodged from the original to 

 other places, and so no longer corresponds to the sought degeneration. 



Therefore this use of M/MicHi-method was rejected. 



I have preferred to study the degeneration or the atrophy, which 

 occur after lesions in the central organ and to compare them with 

 the degeneration or the atrophy after root-lesion. 



I have destruated the nuclei to which the rootfibres go. 



Such lesions however are always complicated, entailing more or 

 less extensive destruction in other systems. It may occur that diffe- 

 rent systems degenerate in many directions and that it appears 

 arbitrary to make a choice among them and to call the one or the 

 other system the secundary system of the injured nucleus sought 

 for. Yet if its results are interpreted with circumspection the method 

 may be useful, for it permits to demonstrate secundary degeneration 

 into a system, which otherwise can only degenerate indirectly. 



