PrENTIss, Neurofibrillar Structures. 17E 
late the neurone theory ; it simply modifies it. There is as yet 
_no direct evidence to prove that these fibrillar networks in the 
neuropil may not be formed by the union of fibrils, each of 
which was developed in a distinct cell. At present we know 
nothing of the origin of the neurofibrillae in the central ner- 
vous system, and, therefore, the presence of independent fibril- 
lae in the nerve elements does not necessitate the abandonment 
of the neurone idea; for such fibrillae, which do not enter the 
cell, may be differentiated in the plasma of the cell processes, 
and be as much a part of the cell as the processes themselves. 
The fundamental experiment of Berne (’98) while of great 
value to neurology, does not in itself prove the neurone theory 
false ; it merely shows that the nerve elements may function for 
some time without their cells; that the cells are not the batteries. 
which generate the nervous current, as was formerly supposed. 
An unprejudiced thinker can but agree with VERWORN 
(: 00) when he says that: ‘‘der Begriff des Neurons und damit 
auch die Neuronenlehre erst dann und nur dann erschittert 
ware, wenn es gelungen, zu zeigen, dass das, was wir als cellu- 
lare Einheit betrachten, in Wirklichkeit aus mehreren Zellen 
besteht.’”’ The only important evidence which at present goes 
to show that the ‘‘cellulare Einheit’’ of the nervous system 
‘‘aus mehreren Zellen besteht,’’ consists of BETHE’s preliminary 
statements of his researches in the histogenesis and pathology 
of the nerve elements. Before passing judgment on BETHE’s 
work we must wait until a full account of it appears. If, as is 
probable, the results of his work prove beyond a doubt that the 
supposed cell individual is the product of many cells, the neu- 
rone theory will be untenable. If not, the neurone theory will 
still remain—a ¢heory; for our present methods have thus far 
failed to prove ‘‘beyond a doubt,” that the nervous system is 
made up of cell units, and nothing but cell units. 
