24 
PRIMROSE : THE ANATOMY OF THE ORANG OUTANG 
hence Bischofif suggested the name of “ omo-cervicalis ” and abandoned 
the old names of “ cleido-cervicalis ” and “ acromio-trachealis ” which 
had been applied to it. Tyson called it “levator claviculae.” Bischoff 
asserts that in all four anthropoids it always arises from the clavicle, 
whilst in Cynocephalus it has been found arising from the acromion 
process and in Macacus from the spine of the scapula. Deniker^ de- 
monstrated the muscle in a foetal Gorilla of the fifth or sixth month of 
gestation, and in a foetal Gibbon of the seventh or eighth month ; in both 
instances passing from the atlas vertebra to the clavicle. It would 
appear that the atlantal attachment of this muscle is very constant in 
anthropoid apes, although Champneys^ described the dissection of a 
Chimpanzee in which the muscle arose “ from the occipital bone 
in a line with the occipital condyles and was inserted into the 
acromial or external half of the clavicle anterior to the insertion 
of the trapezius.” Huxley states that in man^ a separate muscle 
has been seen to pass from the mastoid process to the extremity 
of the acromion, detached from the trapezius, and representing, to a 
certain extent, in man the trachelo-acromial. Testut^ mentions a 
muscle described by Gruber under the name of “ trachelo-clavicularis 
imus” arising from the transverse process of the sixth cervical vertebra, 
and inserted into the clavicle. This Testut considers a variety of the 
omo-cervicalis. In Quain’s Anatomy® is mentioned a detached bundle 
of the levator anguli scapulae passing from the transverse process of the 
upper one or two cervical transverse processes to the outer end of the 
clavicle ; this would apparently represent a true omo-cervicalis in man. 
We may conclude, therefore, that the muscle in question is found in- 
variably in the ape, whilst in man it occurs as a very rare variety. 
The Omo-hyoid muscle was present and possessed similar attach- 
ments and relations to those in man. The supra-scapular artery and 
nerve passed over the superior border of the scapula anterior to the omo- 
hyoid insertion. There was no indication of a transverse ligament 
which exists over the supra-scapular notch in man. In Tick’s® 
Orang the omo-hyoid was weak and there was no intermediate tendon. 
1 J. Deniker, “ Recherches anatomiques et embryologiques sur les singes anthropoi'des jeunes et 
adultes,” Archives de Zoologie exp^rimentale, Sr. 2, Vol. Ill, 1885, pp. 125, 131. 
2 F. Champneys, “ On the Muscles and Nerves of the Chimpanzee (Troglodytes niger) and a 
Cynocephalus anuhis,” Journ. of Anat. and Phys., Vol. VI, 1872. 
3 Loc. cit., Vol. I, pp. 428, 456. 
4 Loc. cit., Vol. I, Part 2, p. 697. 
5 Loc. cit., Vol. II, Part 2, p. 208. 
6 Loc. cit., I, p. 15, 
