308 
ME. ST. GEOEGE MIVAET ON THE SKELETON OE THE PEIMATES. 
prominence marks the attachment of the costo-clavicular ligament, but this is very in- 
constant. 
The Humerus. 
This bone, throughout the order, presents the same main features, the same fossae 
and prominences as those existing in Man. It is absolutely longest in the Gorilla 
and Orang ; Man, the Siamang, and the Chimpanzee successively follow as regards this 
dimension. 
Its length, as compared with the spine, is, as might be expected, greatest in Hylo- 
bates, namely, as 70 or 80 to 100. In the Gorilla and Orang it is from about 60 to 
near 65 to 100 ; in Ateles about 60 ; in the Chimpanzee and Lagothrix about 53 ; in 
Man about 47 ; and in the bulk of the order from between 45 and 30 to 100. In In- 
dris, Lemur, and Perodicticus it is still shorter, though still more than a quarter the 
length of the spine *. 
Compared with the scapula (the latter being measured, as before, from the anterior end 
of the glenoid surface to the posterior vertebral angle) it is nearly three times as long in 
Hylobates, considerably more than twice in Ateles, Lagothrix, and Loris, and slightly 
more than twice in Man, Cercopithecus, and the Pitheciinse. All the rest have it less 
than twice as long (unless possibly sometimes in Simia) ; and in Hapale, Galago, and 
Tarsius its length is less than once and a half that of the scapula. 
The breadth of the middle of the shaft to the length of the bone is mostly as between 
6 and 7^ to 100. In most Cynopithecinae, Perodicticus, Tarsius, and Cheiromys it is 
more than 8 ; on the other hand, in the Pitheciinse, Loris, and Arctocebus it is between 
5 and 6, less than 5 in Ateles, and less than 4, at least sometimes, in Hylobates. 
The width of each extremity of the bone is greatest, relatively, in Cheiromys and 
least in Ateles and Hylobates. But the width of the proximal part (between the tube- 
rosities) is very great, relatively, in Cynocephalus, and of the distal portion, in Galago, 
Perodicticus, and Tarsius. 
The head of the humerus is generally less wide than the extreme width of the tube- 
rosities ; but in the Gorilla they are about equal, and sometimes in Simia f and Ateles, 
and always, apparently, in Hylobates, the head is the wider, being therefore at its rela- 
tive maximum. 
The shaft is often almost quite straight, as in Indris ; often it is curved, as in Man 
and Lemur ; in some it is somewhat convex forwards, as sometimes in Hylobates. 
The articular surface of the head is always directed backwards and inwards $, but in 
Lemuroidea it is almost exclusively backwards, while in Man it is almost as exclusively 
* The bone is measured from the summit of the head to the bottom of the ulnar margin of the trochlea. 
f De Blainville says of the head of the humerus in the Orang, it is “ surtout singuliere par son enormite, son 
diametre etant bien superieur a celui de la tete du femur ” (Z. c. p. 30). 
t Professor Huxley, in his Hunterian Lectures for 1864, called attention to the greater backward direction 
of the head of the humerus in the lower Apes as compared to its condition in the Simiinse and Man. See ‘ Me- 
dical Times’ for 1864, vol. i. p. 672. 
