DEGENERATION AND REGENERATION OF NERVE FIBERS 495 
regeneration—processes which are associated in the functional 
restoration of divided nerves. 
We must still mention briefly a few of the less important 
contributions on the side of autogenous regeneration. Van 
Gehuchten (04) repeated Bethe’s experiments with positive 
results, but did not make a microscopic examination of the 
intervening scar nor attempt to cause the degeneration of the 
new fibers by secondary section of all the nerves going to the 
leg. Ballance and Stewart (01), Fleming (’02), Durante (04), 
and Modena (’05), have made observation in favor of an autog- 
enous regeneration of nerve fibers; but since they present no 
new evidence we need not go into their work in detail here. 
Bethe (07) has attempted to meet the objections raised by 
his opponents, but, as it seems to the present writer, with very 
little success. So far as his paper is not a mere repetition of 
former experiments it may be divided into three parts: (1) He 
considers the facts brought to light by Cajal’s new silver method, 
but we can best take up Bethe’s objections to this method in 
another part of this paper. (2) He reports experiments to show 
that when an axon is divided near its cell of origin no regener- 
ation occurs. That his negative results, so far at least as the 
spinal ganglion is concerned, are to be explained on the basis 
of inadequate histological methods, will be shown in another 
paper when the effects of cutting the nerve roots are taken up. 
(3) He présents experiments designed to meet the objections 
of Langley and Anderson and Lugaro. In spite of the length 
already reached by this review it will be necessary for us to 
analyze these experiments in some detail. 
In reply to Lugaro he presents a case, in which after extirpa- 
tion of all the roots belonging to the nerves going to the hind leg, 
regeneration was recognizable in the peripheral sciatic stump. 
In a young dog he tore out both sciatic nerves, but failed to 
bring the spinal ganglia with them in either case. Several 
weeks later he opened the canal and removed on the left side the 
2to 7 L. and 158. roots. Some months later regeneration could 
be demonstrated in the peripheral stump. But there is one 
