134 
In the agoutis and kangaroos, while the communication was 
absent in certain cases, in others it was present, and closely associated 
with the sympathetic, while in three instances it was impossible to 
distinguish it from the sympathetic at all. 
The same intimate relation to the sympathetic chain was found 
among the cercopitheques. But in this family the communication 
was much larger, as a rule, than in other mammals. 
The variety of communication to which special reference was 
made by SHERRINGTON, was found in one specimen of macaque (macacus 
sinicus 51). 
The results of this investigation suggested that the communi- 
cation between the first and second dorsal nerves is of a composite 
character, being 
partly spinal and 
partly sympathetic 
in nature. 
It was obvious 
that the sympa- 
thetic disturbance 
to the vessels in 
cases of pressure on 
the lowest brachial 
trunk could be 
Fig. 2. Diagram of the hinder end of the Brachial most easily explai- 

Plexus in some individuals. i 
; . ned in the same 
The sympathetic chain and connections as far as their 
communication with the spinal nerves in black. mannerastheother 
The spinal nerves in outline only. svmptoms res- 
A, B, C, D, E, F represent the portions of nerve sub- JE P 
jected to microscopical examination for identification of the Sure on the first or 
relative number of sympathetic and spinal fibres. rudimentary rib) if 
the communication 
in the human were also sympathetic in nature. I therefore undertook 
the dissection of subjects in the postmortem theatre of the Manchester 
Royal Infirmary to investigate this point. In the human subject also 
great individual variation occurs. In some cases the communication 
was absent. In some it was present and these exhibited all the 
varieties which have been described by ELLIOT SMITH, BIRMINGHAM, 
CUNNINGHAM and others, and also that mentioned by SHERRINGTON 
as occurring occasionally. In certain instances the communication 
was closely associated with and presented connections to the 
sympathetic chain. 
