HUNT BY SIGHT, NOT BY SCENT. 335 



they minutely watch the earth beneath with eyes 

 whose keenness has become proverbial in the common 

 expression of " hawk-eyed." 



The study of the habits of these birds is both cu- 

 rious and interesting, and the means by which they 

 discover their prey has given rise to much conjecture. 

 It has been supposed by many that the vulture tribe, 

 at all events, are often guided by their acute sense of 

 smell, but after giving the matter much consideration 

 and long years of observation, we have become con- 

 vinced that this view is an erroneous one. Like the 

 hawk, which descends from on high with one fell swoop 

 upon the defenceless sparrow or partridge, we are 

 convinced that the whole of this class of birds, carrion 

 feeders and all, find their quarry solely by the exercise 

 of sight. 



We think that there can be little doubt that in 

 countries where vultures abound, the atmosphere is 

 always peopled, at different altitudes, by layers of 

 these scavengers; * which are continually wheeling in 

 immense circles during daylight, very often beyond 

 the reach of human eyesight, as they watch the 

 terrestrial landscape with telescopic sight which is 

 within the field of view beneath. 



Travellers who have from long habit instinctively 

 acquired the practice of frequently turning up their 

 gaze towards the sky, will have been certain to remark 

 how often in the cloudless atmosphere of tropical and 

 semitropical lands, they will have observed minute and 



* It is remarkable that the ancient Anglo-Saxon word " sceawian " 

 from which the word " scavenger " is presumably derived, means " to 

 inspect " the original " scavenger " having been an inspector of goods 

 exposed for sale, and also of the streets. (See Chambers' Etymological 

 Dictionary, new Edit., 1891, under the word "Scavenger"). 



