Meyer, Data of Modeini Neurology. 267 



relation to the cell in case of degeneration. In numerous cases 

 of tabetic degeneration which I have examined the negative ex- 

 perimental result of Lugaro after section of the posterior root- 

 fiber is fully corroborated : the spinal ganglia show practically 

 no lesion. Apart from the absence of a necessity for forcing 

 general laws when they do not fit with the facts, we do best to 

 recognize in the segmental afferent neurones a cell-type essen- 

 tially different from the motor in development, mode of conduc- 

 tion and pathological reaction. It is not improbable that among 

 the 'central' cells we shall ultimately find similar or other 

 types which do not fit into the general pattern of a ' motor 

 neurone.' I merely suggest here the peculiar origin of the 

 thalamo-mammillary and the mam miliary-tegmental tract dis- 

 covered by Cajal, and the fibers of the corpus callosum which 

 need study before we formulate tJie law of the neurone. 



The intermediate neurones are very poorly known. Hoche 

 has shown that, in the spinal cord segments, the fibers run 

 closer to the gray matter the shorter they are, and further 

 towards the surface the longer they are ; further, studies of 

 Bruce and others have demonstrated that the anterior ground 

 bundles are more especially in connection with the anterior 

 horn, the lateral ones with the lateral, etc. A detailed study 

 of types of intermediate neurones will only be possible when 

 the cells belonging to the superse'gmental mechanisms are more 

 strictly ascertained. We shall then be able to find out by the 

 way of exclusion just what the intra- and inter-segmental neu- 

 rones are. The conditions are naturally more difficult in the 

 cranial segments on account of the complexity of their func- 

 tions and the presence of the supra-segmental mechanisms, cere- 

 bellum, midbrain and basal ganglia. The simple plan given 

 in the chart of the architecture does not include many anatom- 

 ically well-known entities because their functional relations are 

 in no way elucidated yet. 



In the literature of the Nissl stain we come frequently 

 across the term : ' cell-structure of the motor type. ' It would 

 correspond with Nissl's * stichochromous type,' the cells in 

 which the stainable substance is arranged in lumps or spindles 



