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insertion, which is fascial or tendinous, into the paroccipital process.! 
The sterno-cephalicus has a muscular connection with the rectus 
capitis anticus major. 
The brachio-cephalicus consists of a single sheet attached proxi- 
mally to the external occipital protuberance and the anterior half 
of the hgamentum nuchae. It is continued downwards to the spines 
of the dorsal vertebrae as the trapezius. Distally it is attached to 
the deltoid impression on the humerus and the fascia over the triceps 
and the infra-spinatus. 
In these animals the cleido-mastoid cannot be distinguished 
as a separate entity. The spinal accessory nerve appears between the 
sterno-cephalicus and the brachio-cephalicus near their proximal 
attachments. It is seen in the deeper tissues of the neck emerging 
below the posterior belly of the digastric muscle. 
Between the sterno-cephalicus and the brachio-cephalicus the 
spinal accessory divides into ventral and dorsal branches. The ven- 
tral branch supplies the former muscle, while the dorsal branch is 
distributed to the latter. 
The second cervical nerve forms a communication with the 
spinal accessory and sends branches of supply to the sterno-cephalicus. 
The 8rd, 4th and 5th cervical nerves send branches of distribution to the 
brachio-cephalicus but do not form communications with the spinal 
accessory. ‘The nerve-supply of these muscles is therefore analogous 
to that in the human being. 
The trapezius may be subdivided artificially as suggested by 
WINDLE and Parsons, into three portions (1). These are the highest 
fibres which enter into the formation of the brachio-cephalicus: the 
middle fibres attached to the posterior half of the hgamentum nuchae 
and two or three of the most anterior dorsal spines; and the posterior 
fibres which are attached to a variable number of dorsal spines behind 
the third. 
Our dissections of the above animals show that the areas of 
distribution of the spinal accessory and cervical nerves overlap each 
other. The spinal accessory branches are distributed to the upper 
(brachio-cephalicus) and middle portions of the trapezius. The lowest 
fibres of this muscle derive their nerve-supply entirely from the 
1 Throughout the paper we have used the term paroccipital process in 
the manner in which it is used by FLower (8). 
