Meyer, Data of Modern Neurology. 259 



not involve other cells speaks in favor of an histological inde- 

 pendence, but would not prove it absolutely, nor does it throw 

 any light on the actual mode of interrelation of neurones with- 

 out special microscopic investigation in just this direction with 

 especially delicate methods. 



Dr. Becker in Rastatt was able to stain a few of these cells 

 with a method which does not seem to give constant results 

 and has not been published. Nissl gives a photograph of one 

 of his preparations in the Allg. Zeitschrift fiir Psychiatrie, Vol. 

 54, plate II, Fig. 4, which demonstrates that it is possible to 

 isolately stain fibrils in the motor cells not unlike those de- 

 scribed long ago by Schultze. ' The fibrils run through the 

 cells and processes as a rule in small bundles ; a small number 

 consists of isolated fibrils. Both the individual fibrils and the 

 cables of fibrils take by no means always a straight course ; 

 they form large circles around the nucleus instead of fol- 

 lowing a straight line. The reason for this is not clear. For 

 the proof that the non-stainable substance carries these fibrils 

 the course of the fibers in spirals of the greatest importance.' 

 ' This leads to decussations of all kinds. One portion of all the 

 fibrils does not seem to enter the cell-body at all. Such fibrils 

 and fascicles enter by one process and leave again by the next 

 one. In this case they run along the neighboring surfaces and 

 describe the figure of an U. A difference between the dendrites 

 and neurites could not be established. The fibrils never pene- 

 trate the wall of a nucleus. They always pass it. (Kronthal- 

 Thannhofer's method shows fibrils entering the nucleus and 

 even nucleolus, but according to Nissl these findings are fibrils 

 of stainable substance artificially produced while Becker's fibrils 

 have nothing to do with the stainable substance). Apart from 

 the motor cells no other nerve-cells have shown this structure. 

 It is especially important to note that a cone of origin of the 

 neurite cannot be demonstrated in the Becker cells. This im- 

 plies that the non-stainable substance consists of at least two 

 constituents, fibrils and another substance. ' The great difficulty 

 is now the explanation of these fibrils and their relation to the 

 cell-body. Nissl mentions three possibilities : either the fibrils 



