302 
ME. ST. GEORGE MIYAET ON THE SKELETON OE THE PRIMATES. 
As to the relative proportions of the several margins of the bone, if the axillary 
margin he taken as a standard, then the vertebral border exceeds it by a fourth or a 
fifth of its (the axillary margin’s) length in Man and Perodicticus. It considerably ex- 
ceeds it in the Gorilla, and decidedly so, though to a less extent, in the Chimpanzee and 
in Arctocebus. In Nycticebus the two dimensions are about equal, but in other forms the 
vertebral margin is the shorter, though only slightly so in Mycetes, Ateles, and Pithecia, 
and sometimes in Cynocephalus. In the Orang and Gibbons it is about as 86 or 71 
to 100, while in Lemur and Galago the vertebral margin is only about half the length 
of the axillary one, and the proportion is even less in Tarsius. 
If the anterior (in Man superior) margin be compared in length to the axillary one, 
estimating it by a straight line drawn from the glenoid surface to the anterior vertebral 
angle, it will be found to attain its greatest relative size in the lowest Simiidse, being in 
Cynocephalus sometimes as 107’6 to 100. Its proportional length is also great (91) 
in Perodicticus; in the rest it varies from near this to 61 (Man and Indris about 64), 
except in the Simiinse and Ateles, where it is less, being least in the Chimpanzee, 
i. e. sometimes only as 40 to 100. 
The proportion borne by the anterior margin (superior in Man) to the vertebral one 
is greatest in Tarsius, more than 2 to 1 ; but it is more or less in excess also in 
Cheiromys, the Lemurinee, and the lowest Simiidm, Nyctipithecus, and Chrysothrix. 
The anterior margin is the shorter of the two in Man, Ateles, Mycetes, Pithecia, Indris, 
the Nycticebinee (except Loris) and the Simiinee, and is shortest of all in the Chim- 
panzee. 
The posterior vertebral angle is most acute in Troglodytes niger, where it is some- 
times as small as 22°. In the other Simiinee and in Ateles, it is more acute than in Man, 
in whom it is about 35° or 40° ; but in the rest of the Order it is more obtuse, even 
reaching to 75° in some of the lowest Simiidss. 
The anterior vertebral angle is most marked in Man *, the Simiinse. Ateles, Pithecia, 
the Nycticebinse, Tarsius^ and Cheiromys. In the other forms the vertebral margin 
passes into the anterior one without any marked prominence (Plate XI. fig. 2). 
The direction of the spine of the scapula, with regard to the blade of that bone, may 
perhaps be best estimated by the angles it forms with the vertebral and axillary 
margins. 
The angle formed by it with the vertebral margin is greatest in the Chimpanzee, the 
Siamang, and in Ateles, where it amounts to about 125°, or even rather more ; and in 
Galago and Lemur, where it is about 120°. In the rest of the order it ranges between 
this and a right angle (Man being about 95°), except in some of the lower Simiidse, 
where it falls below a right angle, being sometimes in Cynocephalus as small as 74°. 
* In the Museum of the Royal College of Surgeons are skeletons of a male and female (Nos. 5357 and 
5357a) from South Africa, in which this angle is rounded off, as has been noticed by Professor Gwex, 
Osteol. Catalogue, vol. ii. p. 832. In another female of the same race, however, this angle is exceedingly 
produced. 
