174 INSESSORES. 
extraordinary development of the nasal organs, but 
for what purpose it is designed is not fully known. 
From the earliest ages, the powers of vision of these 
birds have been almost proverbial, and as they seem 
to be constantly on the look-out for some object with 
which to gratify their voracious appetites, it is more. 
than probable that their quickness of sight, rather 
than the sense of smell, assists them in discovering 
their food. Wilson, the American ornithologist, 
speaks of having counted two hundred and thirty- 
seven black Vultures, which had collected for the 
purpose of devouring the carcase of a horse; and 
from his description, we should suppose that nothing 
was left but the naked skeleton long before the least 
effluvia could have escaped from the body to attract 
them.* ( 
Sometimes in the midst of a troop of Vultures may 
be recognized the white head and white tail of the 
* In travelling over the wide deserts of Africa, where 
there is not a blade of grass to tempt a living bird or ani- 
mal, and therefore no inducement for birds of prey to scour 
the wilderness in search of game, should a camel or other 
beast of burden drop under its load in the train of a earavan, © 
in less than half an hour there will be seen high in the air 
a number of the smallest specks moving slowly round in 
circles, and gradually growing larger and larger as they 
descend in spiral windings toward the earth. These are the 
Vultures, but whence they come, or by what sign or call 
they are collected from such a vast height, is mysterious; 
though it is quite possible that it is in consequence of both 
the senses being possessed of an acuteness of which we can 
hardly form any conception. 
