Rd 
nerves from their proximal connection was held by Bethe to have 
no influence towards degeneration of the nerves on the vessels. PREN- 
TICE supports BETHE’s theory in consequence of his own experiments 
on the palatine nerve of the frog (19). 
Max Euvc.LineG found that after section of the sciatic nerve in 
the frog, the vascular nerve plexus around the arteries of the foot 
and skin of the leg degenerate and disappear, leaving isolated the 
cells which BETHE described as nerve cells and which he considered 
to control the nutrition of the plexus (20). 
At the same time LANGLEY independently came to the same 
conclusion. He also recorded the important fact that as sympathetic 
cells tend to travel along the course of the nerve-bundles, care must 
be taken in experiments to destroy all the gangha (21). This may 
have some bearmg on the absence of vascular phenomena in many 
cases of pressure on the lowest brachial trunk. But it also be 
remembered that many sympathetic fibres also reach the plexus 
through the first dorsal nerve. 
The variability in the number of sympathetic fibres passing in 
the communication from the second to the first dorsal nerve will 
affect the symptoms of the lesion. For if a large proportion of the 
sympathetic fibres reach the brachial plexus in this manner they 
will be in a position more liable to injury, namely on the under aspect 
of the combined nerve. On the other hand, should the majority of 
sympathetic fibres join the brachial plexus by way of the first dorsal 
nerve, it is possible that, lying on the upper aspect of the nerve, 
they may for a time at least escape injury. In such a case vascular 
symptoms would appear after the nervous symptoms. 
The results of this research are contrary to what I anticipated 
at its commencement, and do not tally with the views expressed 
by SHERRINGTON except in the prefixing of the forelimb of Man com- 
pared with that of the Cercopithecidae (9). 
It is difficult also to harmonise them with the results of Pro- 
fessor BOLK’S investigation (23). 
They may be of assistance in understanding the difference in 
result obtained by SHERRINGTON on the ape (24) and LANGLEY on 
the cat (24,25). Ican only state that in another investigation of mine 
I have shown that there is no need to invoke prefixing of the brachial 
plexus in Man as compared with Mammals generally as the modi- 
fications entailed by the erect posture are found in the skeleton and 
not in the nerves (16). 
a 
a ae 
a 
false pee 
