1908. | Minute Structure of the Nervous System. 439 
Owing to results thus obtained by experiments with nerve regeneration, 
the just mentioned objections raised to the neurone theory as a result of the 
more or less dubious experiments of Bethe and others, and their incorrect 
- interpretation, which for some time were listened to by the scientific world, 
have thus been refuted. 
As far as I can see, the neurone theory, in its main features, has issued 
victorious from the strife between its supporters and opponents. One may 
still acknowledge that the latter have rendered good negative service, on 
the whole, by their opposition, for they have continually prompted others 
to new researches which have led to the problem being more and more 
thoroughly cleared up. 
The pictures to be obtained by a study of regeneration, as evinced by the 
central nerve-portion, are, besides, very remarkable. The severed axons send 
forth finer or coarser branches, which grope their way onwards along the 
strangest paths and in varying forms. It may be said, in a certain sense, 
that the description by Cajal and Perroncito forcibly reminds us of the 
purely normal growth in the embryo of the axons of the central nerve-cells 
and their buds of increscence, etc. But they also remind us of the pictures 
presented by a large number of the so-called sensitive terminal organs in 
their normal occurrence in the adult individual. The Swedish anatomist 
Ramstrém, of Upsala, who has been subjecting these organs, Meissner’s and 
Ruffini’s, and the Pacinian corpuscles, Krause’s end-bulbs, ete., to a close and 
critical scrutiny, in order to establish their significance, both morphological 
and physiological, has already arrived at very remarkable results, which may 
throw light upon the real nature of these bodies and upon their origin and 
functions. 
There remains, however, to be mentioned another opponent to the 
His-Cajal-Waldeyer neurone theory, in its original form: Held, the German 
histologist, now the real leader of its antagonists. He had tried previously 
to show the occurrence of fine terminal ramifications and end-bud formations, 
by which the ends of some nerves embrace certain nerve-cells, and are 
described as being in direct connection with their substance. 
By a study of the first occurrence of the inner fibril reticulum of the 
nerve-cells, Held formed an opinion as to the first formation of nerve-fibres 
in the embryo, which essentially resembles the one pronounced by the 
German physiologist Hensen, many years ago. Hensen’s doctrine was that 
the nerve-fibres do not grow towards the periphery, but are connected from 
the very beginning both with their central nerve-cells and with the terminal 
organ in the periphery. 
Held has now conceived the idea that the only thing that grows towards 
