252 FACULTIES OF BIRDS. 



geese or any other bird that I have seen ; and, there- 

 fore, quaffer and grope out their meat the most. But 

 then I discovered none of these nerves in round- 

 billed birds. But since, in my anatomies in the 

 country, in a rook, I first observed two nerves that 

 came down between the eyes into the upper bill, but 

 considerably smaller than any of the three pair of 

 nerves in the bills of ducks, but larger than the 

 nerves of any other round-billed birds. And it is 

 remarkable that those birds, more than any other 

 round-billed birds, seem to grope for their meat in 

 cowdung."* 



The facts thus proved by the structure of the or- 

 gan are corroborated by the actions of the birds 

 themselves. There can be little doubt indeed that 

 animals may sometimes be deceived into eating what 

 is unwholesome, or even poisonous. But this, it is 

 probable, happens much more rarely in those en- 

 dowed with acute smell than in others ; for, accord- 

 ing to the beautiful remark of Cicero, borrowed, it 

 is highly probable, from the Greek philosophers, 

 " the nostrils are providentially placed high, because 

 odours have a tendency to rise, and are also near 

 the mouth for the purpose of descriminating food 

 and drink." Even very young ducks, accordingly, 

 will reject from the mud in which they may be fish- 

 ing such substances as they judge by smell to be 

 unfit for food, while they will eagerly swallow a bit 

 of biscuit which, for the sake of experiment, may 

 be concealed among the mud ; and they will as ea- 

 gerly seize and swallow any animal garbage which 

 they find in the same place, and which has just been 

 rejected by their fellow-swimmers the swans, whose 

 food is wholly vegetable.! Dr. Darwin was there- 

 fore in some degree right in the following remarks, 

 though he evidently carries his principle to ex- 

 tremes which facts will not altogether justify. 



* Phil. Trans., No. 206. f J. Rennie. 



