502 
Proceedings of the Roj/al Irkh Academy. 
The rhomb oideiis has no occipital origin : its lesser (cervical) part is 
from three, and its major or dorsal part from four spines, but they 
are not separable ; and the whole muscle is larger than it is in the 
chimpanzee. 
The serratus magnus arose from ten ribs, and its levator anguli 
scapulae segment was attached to three cervical transverse processes (4- 
6) ; the whole muscle equalled the rhomboid and the trapezius in weight ; 
it is larger proportionally in the chimpanzee, in which the levator 
segment is more distinctly separable. I could not divide the serratus 
in the gorilla as I did in the chimpanzee, nor did it extend as far as 
the twelfth rib in the former, as it did in the latter. 
The latissimus dorsi is attached to the spines of the four lower 
dorsal vertebrae, to the three lower ribs, and to the lumbar fascia. It 
detached a dorsi epitrochlear element, as a very thin membrane, twenty 
grains in weight, to be attached to the fascia of the forearm : this is 
rather larger than in the chimpanzee. The deep spinal muscles are 
like those of man and the chimpanzee. The deltoid is a single 
separate muscle as in man, very much larger than in the chimpan- 
zee. The great pectoral has a nearly separate clavicular portion, and 
so, not like the chimpanzee, it was smaller than the deltoid, while in 
my chimpanzees it was larger. The lesser pectoral was inserted into 
the coracoid process on each side, and had no trace of the variability 
described in this muscle in the chimpanzee {loc. eit.) ; it arose from 
the third, fourth, and fifth ribs. The subclavius lay under a very 
strong costo-coracoid membrane, but was exceedingly small. The 
tendon of the lower pectoral did not split the costo-coracoid membrane. 
The supraspinatus was to the infraspinatus as 1 to 2, while in the 
chimpanzees they were as 10 to 15 and as 11 to 16; teres minor is 
one-third of the infraspinatus. The subscapularis is large, fully equal in 
size to the sum of the dorsi- scapular (spinati) muscles — not quite so 
much in the chimpanzees (27 is to 32). There is no subscapulo-humeral. 
The teres major is moderate, one-third the latissimus dorsi ; it is rather 
less in the chimpanzees. They are arranged as in man. The coraco- 
brachialis is the middle variety, like the human normal muscle, and 
has the musculo-cutaneous nerve superficial to it ; it is larger than in 
the coraco-brachialis. 
In the shoulder joint there is a strong gleno-humeral ligament 
(Plate XXIX., Fig. 2, E. I.) and an inferior (Humphry's) ligament. 
The biceps has its usual two heads, of which the glenoid was to 
the scapular as 33 to 18; this muscle is nearly twice as large pro- 
portionally as in the chimpanzee. The brachialis is anterior and not 
external, it equals the glenoid biceps in weight. The three heads of 
the triceps were more or less combined in the gorilla and chimpanzee. 
The extensors are to the flexors in the gorilla as 21 to 17. In the 
chimpanzees they are as 19 to 13. The anconeus is small and distinct. 
There is no anconeus internus. 
In the forearm the pronator radii teres had a coronoid head (Plate 
