2 SIMIID^. 



I first met with this species in Upper Burma, in passing through the magni- 

 ficent defile of the Irawady, below Bhamo, where the river is enclosed by high hills, 

 covered with dense forest, for about fifteen miles of its course. It was early morn- 

 ing and the air was resonant with the loud calls of this Gibbon ; large troops were 

 answering each other from the opposite banks, and the hills echoed and re-echoed 

 the sound. The Hoolock is also common on the Kakhyen hills, on the eastern 

 frontier of Yunnan ; and, there, too, my attention was called to them at daybreak 

 when they passed up from their sheltered sleeping- ground in the deep and warm 

 valleys to heights of about 4,000 feet. We, in the middle distance, first caught a 

 faint murmur of voices; but every minute it became more and more distinct, 

 till at last the whole troop rushed past in a storm of sound, vociferating "whoko !" 

 " whoko !" and in a few more minutes their cry was heard far up the mountain-side. 

 Considering that their progress is almost exclusively arboreal, the rapidity with which 

 they make their ascent is wonderful. 



Associated with this arboreal habit of progression, we find that S. hoolock 

 derives its nourishment from leaves, insects, eggs and birds, the essential features 

 of sylvan life. Prom a series of observations made in the Zoological Gardens, 

 Calcutta, on the food of this species, w^e learn that it eats, with evident satisfaction, 

 the leaves of the following trees : Moving a pterygosperma, Gaertn., Spondias mangi- 

 fera, Pers., and Ficus religiosa, Linn. Like the leaf-eating monkeys, such as Semno- 

 pithecus entellus, it devours with avidity the leaves of JBeta vulgaris, Mog., and 

 those of the aquatic convolvulus, I. reptans, Poir. With the Ourang-outan it also 

 manifests a decided predilection for the bright-colom^ed flowers of Ccmna indica, 

 Linn. 



It is no new fact that H. hoolock, hke its congener S. lar, has a marked par- 

 tiality for spiders and their webs, which become tangled in its long slim fingers, and 

 that orthopterous insects are regarded by it with special favour, over which it utters 

 its peculiar cry of satisfaction. Eggs also are to it a honne louche. It was first in 

 the Calcutta gardens that I became aware of the circumstance that small living 

 birds were devoured by it with a method and eagerness wliich has left no doubt 

 in my mind that this species, in its natural state, must be a scom'ge to the feathery 

 tribe. The living bird being seized by the body, the work of destruction is begun 

 at the head. The hoolock in so doing forcibly reminded me of the course pursued by 

 that nocturnal nest-harrier Nycticehus tardigradus. 



As is well known, this species has the most westerly distribution of the mem- 

 bers of the genus. Pemberton,^ who w^as an accurate observer, records that it 

 occurs in the lower ranges of Bhutan ; and a remark of Hodgson's" would seem to 

 favour the supposition that it occasionally finds its way even to the sheltered vaUeys 

 of Nepal, as he mentions that his collectors were alarmed in the Kachar^ by the 



' Journ. As. Soc. Beng. vol. viii. 1839, p. 272. 2 x. c, 1832, p. 339, foot-note. 



^ L. c, p. 339. Hodgson applied the name Kachar to the northern region of Nepal. 



