Meyer, Data of Modern Neurology. 123 



Forel have done conclusively ; he demonstrates the blind ar- 

 borizations or end-brushes of so many kinds of nerve-fibers and 

 the connection of the latter with cell-bodies in the cerebellum, 

 the medulla, olfactory bulb, retina, optic centers, the great 

 sympathetic, the cerebral cortex, that the concept and the de- 

 tailed data are established beyond doubt ( sin sombra alguna de 

 duda^). 



The principal generalizations which we can derive from 

 Cajal are as follows : 



1. There is no substantial continuity between the pro- 

 cesses of different nerve-cells. The nerve-elements represent 

 cell-units, for which he accepts Waldeyer's term 'neurone'. 



2. While Golgi assumed that the protoplasmic processes 

 of nerve-cells had a purely nutritive function, Ramon y Cajal 

 renders it probable that the protoplasmic processes are those 

 parts of a neurone with which the arborizations of other neu- 

 rones come most likely into contact and that the contact with 

 the zoW-body itself is exceptional, being found only in those 

 cells in which there are no protoplasmic processes (spinal gan- 

 glion, retina). 



3. The spreading of impulses received is celluHpetal in 

 the protoplasmic processes and centrifugal in the axis-cylinder 

 (law of dynamic polarization). 



We must mention here that one of Golgi 's chief discover- 

 ies is the demonstration of fibrils or collaterals which branch at 

 right angles from the nerve-process of almost every cell soon 

 after its origin. The conception of Deiters, that the nerve- 

 process was characterized by having no branches before its final 

 termination, was modified by Golgi, inasmuch as he found that 

 not only the protoplasmic processes have branches but also the 

 nerve-process ; the difference lies in the branching at acute an- 

 gles in the case of the dendrite, and at right angles in the case of 

 the collaterals ; further, it is easy to see that the dendrites taper 

 towards the periphery, whereas the collaterals are smooth and 



'Dr. D. Santiago Ramon y Cajal, Nuevo concepto de la Histologia de los 

 Centros Nerviosos, Barcelona, 1893. 



