436 E. C. MacDowell. 
toralis is common in all anthropoid apes. Beddard describes 
this muscle in Anthropopithecus calvus as being relatively as 
large as in man, and Hartmann says that it is well developed in 
anthropoids generally. 
B. MuvuscLES oF THE ARM 
The Latissimus dorsi arises in my chimpanzee from the four 
posterior lumbar vertebrae closely mingled with the posterior 
border of the trapezius, from the crest of the ilium, and by inter- 
digitations with the obliquus externus abdominis from the four 
posterior ribs. The muscle is inserted into the bicipital groove 
by a strong flat tendon 2 em. wide and 4 cm. long, superficial to 
the proximal half of the broad insertion of the teres major. There 
is no connecting fasciculus between these two muscles. The 
fibers of the Latissimo-condyloideus (dorsi-epitrochlearis) arise 
from the flat tendon of the latissimus dorsi at its distal end, and 
continue down the arm in a belly 1.8 cm. in diameter to be firmly 
inserted by a strong flat tendon 4 em. long into the internal con- 
dyle of the humerus. This muscle receives a fasciculus from the 
coracobrachialis. 
In the baboon, the tendon of the latissimus dorsi (fig. 1, F) 
is entirely distal to that of the teres major (fig. 1, R). <A large 
fasciculus (fig. 1, V) is given off from the superior border of the 
latissimus dorsi to be inserted into the lower border of the broad 
flat tendon of the teres major before the insertion of the former 
into the humerus. The latissimo-condyloideus (fig. 1, U) is 
large and well developed. It- arises mainly from the muscle 
fibers of the latissimus dorsi. Indeed, many of the fibers of the 
latissimus dorsi seem to be continuous with those of this muscle. 
It is inserted into the long head of the triceps and the brachial 
fascia just above the elbow. In this way, the insertion of the 
latissimus dorsi is practically extended to the olecranon process, 
and a very long and powerful muscle is formed, which may be called 
the Latissimo-dorsi-condyloideus. In the Macacus, the latissimo 
condyloideus is very poorly developed. Its fibers are inserted 
directly into the fascia over the triceps. 
