OBSERVATIONS ON MAMMALS 247 



see stones come hurtling down the cliff as though they 

 were missiles thrown at the intruder. For a long time 

 I doubted the statement of the hillmen that the 

 monkeys actually did employ stones as weapons to 

 drive away an enemy ; I thought that the stones must 

 be simply dislodged by chance. But I have no doubt 

 that the hillmen were correct. For at last I saw one 

 of these monkeys deliberately tilt up a large stone 

 and roll it towards me down the slope. This I take 

 to be the most rudimentary manifestation of the more 

 elaborate instinct that employs weapons as a mode of 

 protection or offence. It is the first trace of that higher 

 judgment possessed by other monkeys of selecting 

 stones of suitable size and shape to use as weapons 

 against their foes, or of the skill with which the female 

 orangutan breaks off branches and spiny fruits from the 

 trees to hurl them to the ground in a shower of 

 missiles. 



The only other monkey that I observed in the dis- 

 trict was the langur, Presbytis schistaceus. I saw 

 very little of it. It keeps to higher altitudes than the 

 Bengal monkey, usually remaining above 6000 feet, 

 and I have seen it near the tree limit at 11,000 feet 

 traversing the fields of snow. It is a handsome 

 animal of a slate colour above, yellowish beneath, 

 and carries a long, slightly tufted tail. Its black face 

 is very conspicuous, since it is encircled in a white 

 fringe. It stands two and a half feet in height, while 

 its tail is about three feet in length. The langur 

 seems more arboreal than the Simia. Large troops 

 composed of both adults and young leap about the 

 trees and make a great noise as they crash heavily 

 through the forest;. It feeds on grajn, fruit, leaves 



