NOTES ON THE HABITS OF THE HGOLOCK. 701 



hut the moment you leave the path or look up at them there is a dead silence 

 and scarcely a leaf stirs, until, tired of waiting, you move on again. 



The cry of the Hoolock is a characteristic sound in the Cachar jungle. It is 

 a very pleasing note, rising and falling in intensity, and reminding one somewhat 

 in its rhythm of a pack of beagles giving tongue on a scent which is waxing and 

 waning in strength, as a larger or smaller number of the band join in the chorus. 

 It is heard chiefly in the early morning, then all through the heat of the day 

 there is silence, but towards evening, as the sun sinks, you may hear it again. 

 Hooloo ! Hooloo 1 Hooloo 1 with the accent on the Hoo syllable, is supposed to 

 describe the sound, but it is really quite indescribable in writing. 



As in other species of apes, there is a special modification of the larynx, which 

 acts as a sort of resonating-box, and helps ( I suppose ) to make the sound carry 

 as it does, long distances. There is also a peculiar arrangement of the upper 

 aperture of the larynx, with its small and inadequate looking epiglottis, which 

 more resembles the arrangement in birds than the leaf-like epiglottis in man. 



As, day after day, I have ridden through the jungle, it has seemed to me that 

 the Hoolocks work their ground systematically in their search for food, just as 

 the planter plucks one section of his tea to-day and another section in a distant 

 part of the garden to-morrow. For I have found them filling the air with their 

 cries along a particular stretch of jungle-road one day, whilst the next day not 

 one was to be heard ; then, perhaps, a week later they are back again in the same 

 place. Living as they do in communities, they are constantly on the move, and 

 from what we know of their great intelligence, it seems to me highly probable 

 that their movements are guided by very definite plans, and that very probably 

 they have some sort of government system. 



There is a point about the Hoolock that strikes me as very extraordinary 

 and that is the fact that he cannot swim. I had been told this by both natives 

 and Europeans, but I confess I was somewhat sceptical about it until I tried 

 experiments myself. We put a full-grown Hoolock into a big tank in 10 feet 

 of water. He struggled helplessly, as a boy would before he learns to swim. 

 He sank twice, with head thrown back and arms waving frantically, and we 

 were obliged to rescue him almost asphyxiated and choking in the most human 

 way. 



This weakness he shares with man, but I do not know whether (or not) it has 

 been noted in the other anthropoids. 



It is a significant fact that the range of the Hoolock is bounded by two vast 

 rivers, the Brahmaputra on the north and the Irawaddi on the south. It may 

 well be that, with his natural aversion to water, these rivers have confined him 

 to the comparatively limited stretch of country he occupies. Travelling high up 

 in the jungle, he could swing easily across the ordinary streams which would 

 come in his path without having to take to the water. The monkeys of India 

 take readily to water, and it is a pretty sight to see them spring out from a 

 Io e ty overhanging bough and drop, one after another, with a splash into the 

 stream, and strike out boldly for the further bank. 



