Macacus sancti-johamis, Gray (in part), Cat. Monkeys and Lemurs, B. M. 1870, Appendix, p. 129.
Macacus rhesus, Sclater, Proc. Zool. Soc. 1871, p. 222.
Pur thick and dense, dark olive-green throughout, finely yellow-speckled;
no rufous on the hind quarters. Ears small and clad, a strong ruff-like beard. Tail
in adult about a foot long and well clad.
This Macaque appears to be restricted to the Island of Pormosa, where it
was discovered by Swinhoe. Its round, flat face, dark olive-green, uniformly
annulated fur, and the complete absence of any rufous tint on its hind quarters,
are the external characters which separate it from M. rhesus and its near ally
M. lasiotis from the mainland of China, while, by these features, with the
exception of the last, it is distinguished from M. assamensis, which, moreover,
unlike M. cyclopis, has the shoulders suffused with yellowish. The tail has much
the same proportions to the body as in M. rhesus, but it is more bushy. I t is
doubtful that the forehead is any more entitled to be called bare than is the forehead
of M. rhesus, as it is clad to the supraorbital ridges, along which also occur a few
long black hairs, as in the rhesus group of Macaques generally. Unlike M. rhesus,
the hair behind the mouth, and below and behind the ears, is markedly annulated,
and there is a strong ruff-like beard, as in M. assamensis. The ears are moderately
large, well clad and tufted. The fur generally is fine and dense, moderately
long, and not longer on the shoulders than on the rest of the body.
Dr. Murie, in discussing the affinities of this form, has favoured the view that the
female, during the period of heat, is subject to a much greater tumidity and swelling
of the hinder parts than ever occurs in M. rhesus, but the description which he
has given of this curious phenomenon as it occurs in M. cyclopis is no exaggerated
account of what I have observed in M. rhesus on a number of occasions in different
animals. In some of these, great tumour-like swellings had attained such
dimensions, and had so involved the whole of the sacral region, the upper portion of
the thighs, the base of the tail, and all the back parts of the limbs even
to near the heel, that the hinder quarters seemed so weighed down with the
burden as to give the animal a waddling gait. This monstrous development I have
observed both in animals in confinement in India and also among semi-ferine
monkeys living in colonies that had attached themselves to villages in the North-
West Provinces. In M. rhesus there is no modification or particular adaptation
of the pelvis for the support of these temporary enlargements of the subcutaneous
tissues which invest it posteriorly in the female, but Dr. Murie holds that such an
adaptation of the pelvis does occur in M. cyclopis. The materials, however, from
which Dr. Murie’s deduction is derived are not so reliable as could be wished, and he
mentions that the modifications which these pelves of M. cyclopis manifest on the
ordinary type of the healthy Macaque pelvis might suggest the possibility that they
are the product of disease, and he states that the long bones of the male skeleton
are unusually porous, but that the female skeleton is solid, and does not exhibit any
signs of mollities ossium. But the very circumstance that it should have occurred
to Dr. Murie that his statements might be objected to on the ground that a softening
or other diseased condition of the bones might suggest itself to other observers
as the cause of the abnormality of the pelvis of M. cyclopis is in itself an
acknowledgment of the weakness of the facts on which his generalisation is
hased. Either the abnormality conforms to one of the forms of pelvis generally
induced hy disease, or he was not perfectly convinced that the bones of the female
pelvis were perfectly healthy, although, as he states, they were free from mollifies
ossium. The circumstance, moreover, that he describes the long bones of the male
skeleton as more than usually porous and soft, and that its pelvis was not so firm as
to be consistent with robust health, naturally detracts from the value of his statement
regarding the curvatureipf the long bones which he considers to distinguish the
monkey from M. rhesus, and it thus can hardly he aoceded that he has demonstrated
that M. cyclopis possesses characters decidedly differing from those of the ordinary
rhesus monkey.
I have examined the same materials on which Dr. Murie has founded his
generalisations regarding the supposed anatomical differences of M. cyclopis
from M. rhesus. The male skeleton is unusually porous and soft, and the female
bones, although they have none of the porous character of those of the male, are
extremely light, and the pelvis appears to me so deficient in earthy constituents
that it has a membranous appearance. The pelvis of the male, on the other
hand, is very porous, and has almost a friable aspect, which condition seems to
explain its less divergence from the normal pelvis, whereas the more membranous
character of the female pelvis fully accounts for its greater divergence from
the rhesus type. The bony substance, however, of each is very different in consistence
from the hard, heavy, compact structure of a healthy pelvis.
In the normal pelvis of M. rhesus and its allies, a straight line drawn from
the anterior superior angle of the iliac portion of the hone to the inferior end of the
tuberosity of the ischium conforms to the external border of the ilium and cuts off
the lower third or nearly so of the acetabulum and the upper third or middle
of the thyroid foramen, according as the tuberosity of the ischium is thrown
upwards.
In these details of its course across the acetabulum and thyroid foramen it conforms
to the course pursued hy a line drawn between similar extreme points in the
human pelvis.
In M. cyclopis, however, such a line does not run parallel to and touch the
anterior border of the iliac portion of the hone, but encloses between it and itself
in the female an elongated oval space, and this occurring also in the male, but to a
more limited extent, proves that both pelves have the same kind of abnormality
depending on the downward and inward bending of the iliac portion of the bone
on itself. There can be no doubt that this alteration in the normal relations of the
constituent parts of the pelvis gives rise to a greater interval between the root
of the tail and the tuberosity of the ischium, hut, on the other hand, there
is a narrowing of the interval between the callosities associated with a marked
general contraction of the hinder portion of the pelvis, thus reducing instead