THE VULTURE. 27 



pour forth his sweet and vernal notes nearer to 

 them. 



But to return to the vulture. After the repeated 

 observations I have made in the country where it 

 abounds, I am quite satisfied that it is directed to 

 its food by means of its olfactory nerves coming in 

 contact with putrid effluvium, which rises from 

 corrupted substances through the heavier air. 

 Those are deceived who imagine that this effluvium 

 would always be driven to one quarter in the 

 tropics, where the trade-winds prevail. Often, at 

 the very time that the clouds are driving from the 

 north-east up above, there is a lower current of air 

 coming from the quarter directly opposite. This 

 takes place most frequently during the night-time, 

 in or near the woods ; and it often occurs early in 

 the morning, from sunrise till near ten o'clock, when 

 the regular trade-wind begins to blow. Sometimes 

 it is noticed in the evening, after sunset ; and, now 

 and then, during the best part of the day, in the 

 rainy season. In Guiana there is a tree called hay- 

 awa : it produces a deliciously smelling resin, fit for 

 incense. When the Indians stop on the banks of a 

 river for the night, they are much in the habit of 

 burning this resin for its fine and wholesome scent. 

 It is found in a hardened lumpy state, all down the 

 side of the tree out of which it has oozed. It is 

 also seen on the ground, at the foot of the tree, in- 

 corporated with the sand. When we had taken up 

 our nightly quarters on the bank of the Essequibo, 

 many a time we perceived this delightful fragrance 

 of the hayawa, which came down the bed of the 



