1903.] ON THE HABITS OF THE HOOLOCK. 187 
6. Notes on the Habits of the Hoolock. 
By Geo. Canpirr, M.B.Cantab.? 
[Received January 20, 1903.] 
The Hoolock (Hylotates hoolock) is one of the most interesting 
of the family Simiidee, and is perhaps not so familiar to naturalists 
at home as are some other members of the family, as, owing to its 
extreme delicacy and the great difficulty experienced in keeping it 
alive in confinement, it does not often find its way into European 
collections. Even in the Calcutta Zoological Gardens it is difficult 
to keep Hoolocks alive for any length of time. They often 
succumb to pneumonia, or if they escape actual disease they mope 
and die from the effects of confinement, or possibly from depri- 
vation of some article of diet which in the wild state they have 
been accustomed to. I have ventured therefore to submit to the 
Society these short notes, made from the point of view of a field- 
naturalist rather than from a scientific aspect. 
The Hoolock is clothed all over with a fine soft hair, which, 
perfectly black in the male, in the female shows a greyish tint, 
especially over the back. This uniform dark colour is only 
relieved by narrow horizontal streaks of white hair above the eyes. 
The face, palms of the hands, and soles of the feet are devoid of 
hair, and here the black skin is smooth and finely wrinkled and as 
soft as the finest kid. 
The hallux and pollex have a flattened nail, the remaining digits 
have the nail laterally compressed and resembling a claw. 
There is no tail. Ischial tuberosities and cheek-pouches are 
absent. 
When the Ape is sitting, the vertebral column presents a single 
marked curve with the convexity backwards. On the ground the 
Hoolock has a very characteristic gait. He goes along in a sort of 
shambling waddle, with legs bowed and knees bent, the soles of his 
feet applied flat to the ground with the hallux widely abducted, both 
arms being carried upwards and extremely abducted as if to balance 
himself. He cannot get up any speed, and invariably swings up 
into the first tree he comes to, where his movements are suddenly 
changed from extreme awkwardness to extraordinary grace and 
agility. 
He swings along to the thinnest part of a bough, or to the 
slender end of a bamboo, until it bends to his weight, then with a 
swing and a sort of a kick-off he flies through the air, seizing 
another bough and swinging along it with the unerring accuracy of 
a finished trapeze performer. I fancy he does very little walking 
in the wild state, for I have never seen a wild Hoolock on the 
ground. Moreover, they are only found in the dense jungle where 
the ground is everywhere covered by tangled vegetation. It is 
puzzling to me why these anthropoids, being so entirely arboreal 
1 Communicated by F>G. Parsons, F.Z.8, 
