700 PRIMATES 
to allude to all the members of the first four families as Apes, in 
contradistinction to Man. In respect to relative size the extremes 
are found in the Gorilla on the one hand and Hapale on the other; 
the difference in this respect between these two forms being greater 
than that between Man and a Squirrel. The relative proportions 
between the limbs and the body, and also between the fore and 
hind limbs, are subject to great variation. Thus in Hylobates and 
Aieles both pairs of limbs are much elongated; in the former case 
the pectoral being much longer than the pelvic pair (Fig. 335). 
In other cases, as in the Orang (Fig. 354), while the arms are very 
long, the legs are short; but in the ‘subfamily Cercopithecine both 
pairs are short and subequal. Only in the Hapalide and some of 
the Cebide are the legs proportionately as long as in Man. 
The tail is as much as three times the length of the body in 
Aleles ; while in the Simiide it is totally absent. In the majority 
of genera it is long in all the species; but in some cases, as in 
Macacus, it may be either long, short, or absent in the different 
species of a single genus. 
Equally marked variations occur in the shape of the head. 
Thus in Ateles it is rounded; while in the Orang it is elevated 
vertically ; in Chrysothrix it is produced posteriorly ; and in the 
Baboons (Cynocephalus) it is characterised by the great production 
of the muzzle and the terminal position of the nostrils, whereby a 
characteristic Dog-like form is assumed. The eyes are always 
directed forwards, and are never more separated from one another 
than in Man, although, as in Chrysothriz, they may be closer 
together. They are of very large size in Nyctipithecus, while in the 
Baboons they are relatively small in proportion to the size of the 
head. The ears are invariably well developed, and are usually 
pointed at their postero-superior angle. Those of man are charac- 
terised by the soft depending portion known as the “lobule,” of 
which there is a rudiment in the Gorilla. In the majority of Apes 
the nose is but very slightly prominent; but it attains an extra- 
ordinary development in Nasalis larvatus, and is scarcely less 
remarkable in Semnopithecus rowellane (Fig. 349). Among the 
Gibbons the Hoolock has a distinctly aquiline nose. The nostrils 
are terminal in the true Baboons; and while in all the Old World 
Apes they are approximated, in those of the New World they are 
separated by a broad septum. With the exception of the Orang, 
the lips of the Apes are thin. 
The pollex makes a nearer approach in form to the human 
thumb in the Chimpanzee than in any other Ape. Man differs 
from all the Apes in having the hallux frequently longer instead of 
shorter than the other digits of the foot. The hallux of the Orang 
is peculiar in having no nail, but in other cases the nail is flat; the 
nails of the other digits of the Apes are never quite flat, and in 
