14 



they left close to their tent on the surface of the 

 earth. In less than one hour after it had been 

 killed, at the time that the sky was so serene 

 that there was not a cloud observable, a small 

 dark spot at an immense distance in the air, 

 attracted their notice; this spot gradually in- 

 creased in size, and they soon found that it was 

 a Vulture which was flying in a direct line 

 towards the dead animal, on which it im- 

 mediately alighted for the purpose of devour- 

 ing it. In less than an hour's time, seventy vul- 

 tures came from all directions, some horizontally, 

 but the major part descended from the upper 

 regions, in which a few minutes before no ap- 

 pearance of them was discernable. 



Such, indeed, is the exquisite sensibility of 

 the eye of birds, that they are provided with a 

 membrane, which they are enabled to spread 

 over the external surface of it, so as to pro- 

 tect the retina from the injuries which it might 

 sustain on particular occasions from the irrita- 

 tion of the solar rays. Saumarez. 



