40 Ornithology. 



' The toucan ranks next to the vulture in discerning 

 whether by smell or by sight, the carrion on which it feeds. 

 The immense size of its bill, which is many times larger than 

 its head, was supposed to present, in its honeycomb texture, 

 an extensive prolongation of the olfactory nerve, and thus to 

 account for its power of smelling at great distances; but, on 

 accurate examination, the texture above mentioned in the bill, 

 is found to be a mere diploe to give strength to the bill. Now 

 the eye of this bird is somewhat larger than the whole brain ; 

 and it has been ascertained by direct experiments, that, where 

 putrid carrion was inclosed in a basket, from which effluvia 

 could freely emanate, but which concealed the offal from 

 sight, it attracted no attention from the vultures and other 

 birds of prey till it was exposed to their view, when they im- 

 mediately recognized their object, and others came rapidly 

 from different quarters of the horizon, where they were invisible 

 a kw minutes before. This sudden appearance of birds of 

 prey, from immense distances, and in every direction, however 

 the wind may blow, can only be accounted for by their 

 soaring to an attitude. In this situation their prey on the 

 ground is seen by them, however minute it may be, and 

 their appearance is merely their decent from high regions of 

 the atmosphere, to within the scope of our optics.' 



LuBRicATiOiN OF THK Feathers OF BiuDs. The fcatlicrs 

 of birds would constantly imbibe moisture of the atmosphere, 

 and, during rain, absorb so much wet, as would almost, if not 

 wholly, impede their flight, had not the wise economy of 

 nature obviated this by a most effectual experiment. They 

 are furnished on the rump with two glands, in which a 

 quantity of unctuous matter is constantly secreting. This is 

 occasionally pressed out by means of the bill, and used for 

 the lubrication of the feathers. The birds which share, as it 

 were, the habitations of man, and live principally under cover 

 do not require so large a supply of this fluid, and, consequent- 

 ly, are not provided with such a large stock of it as those that 

 rove abroad, and reside in the open element. Hence poultry, 

 when wet, assume a ruffled and uncomfortable appearance. 



