The Myology of Chimpanzee and Baboon. 439 
that this muscle is typically composed of three parts, all of which 
arise from the coracoid process. The upper head is regularly lack- 
ing in man, and this seems to be the case in my chimpanzee. 
However, it is present in the baboon and in the Macacus. Champ- 
neys, Hepburn, and Beddard describes two divisions in the chim- 
panzee, while Duvernoy and Vrolick describes one. Hepburn 
found elements of all three divisions in his gorilla. Lubosch found 
two divisions in a human body (see table I). 
TABLE I 
ANIMAL REPORTED BY CORACOBRACHIALIS 
Chimpanzee Hepburn | 2divisions 
Chimpanzee Champneys | 2divisions 
Chimpanzee Beddard 2 divisions 
Chimpanzee Duvernoy _ 1 division 
Chimpanzee Vrolick | 1 division 
Chimpanzee Author | 1 division 
Baboon Author | 2 divisions 
Macacus Author | 2divisions 
Gorilla Hepburn | elements of 3 divisions 
Orang Primrose 2 divisions 
Typical Mammal Wood _ 3 divisions 
Man Lubosch 2 divisions as a variation 
The Triceps Brachii has but little variation from the muscle in 
man. In the chimpanzee, the three heads are intermingled a 
short distance from their origins. The long head arises from the 
axillary border of the scapula for nearly its whole length, and dis- 
tally from the deltoideus and the surrounding fascia. This origin 
is semi-cartilaginous. Its belly is fiat and wide before its incor- 
poration with the otherheads. It lies between the teres major and 
the deltoideus. The long head in the baboon arises by a tendon 
closely associated with the muscle fibers from the axillary border of 
the scapula between the teres major and teres minor and is lost im- 
mediately in the main belly of the triceps; thus it has a triangular 
shape. A flat slip of muscle 1.5 cm. wide arises from the axillary 
border of the scapula just beyond the distal limit of the origin of 
the long head. This slip extends half way down the arm parallel 
to the long head of the triceps and is inserted into the fascia cover- 
