7 
spinal nerves. These last-mentioned fibres obtain a distal attachment 
to the fascia over the infra-spinatus and to the spine of the scapula. 
In our specimen of peccary we found considerable differences 
from the condition in the afore-mentioned ungulates. In this animal 
the sterno-cephalicus consisted of a large and thick sterno-occipitalis, 
which was supplied by the ventral branch of the spinal accessory 
alone, and not by the second cervical nerve as in the previously men- 
tioned animals. No representative of sterno-massetericus was present. 
The brachio-cephalicus was composed of portions corresponding 
to cleido-mastoid, cleido-occipitalis and trapezius, all of which were 
supplied by the dorsal branch of the spinal accessory. To this muscle 
were distributed, in addition, branches from the second and third 
cervical nerves, which formed a sub-muscular plexus with each other 
and with the spinal accessory. 
In the main these descriptions are harmonious with those of 
WINDLE and Parsons (1) and of SISSON (4). 
By means of experiments on the bodies of these mammals we 
found that very free movement of the fore-limb in an antero-posterior 
plane could not possibly injure the nerves to the brachio-cephalicus. 
When, however, the limb was forcibly abducted the cervical nerves 
to the brachio-cephalicus were stretched and lable to damage, but 
the spinal accessory, because of its length, invariably escaped injury. 
The clinical application of this fact has been dealt with in a recent 
paper (9). We included the peccary in the present research in view 
of the experimental studies on the suidae by LESBRE and MAIGNON (2). 
These authors have shown that in the pig tribe and in horses and 
cows, the spinal accessory is purely motor in function, while the supply 
to the sterno-cephalicus and the brachio-cephalicus from the cervical 
nerves consists entirely of sensory fibres. What is true of these animals 
may be taken as correct for the majority of her bivors and is 
probably true of all ungulates. (There may be some difference in 
other animals e. g. dogs.) It is significant, in this connection, that the 
spinal accessory does not supply the lowest fibres of the trapezius. 
In the human being the upper fibres of the trapezius are supplied 
by the spinal accessory, while the lower. fibres obtain their supply 
from the 3rd and 4th cervical nerves. The lowest fibres of all are 
said also to be supplied by the spinal accessory (see PURVES STEWART 
(3)) but it is to be noted that these fibres are frequently absent 
or rudimentary. ‘The clinical manifestation of section of the spinal 
