STRUCTURE OF THE MOUTH. 961 
as an essential character of Accentor, because it is 
manifested by an external conformation, which in- 
dicates such habits. This instance, out of number- 
less others, is a convincing proof that not even a 
difference in the nature of their food will invariably 
or completely detach insectivorous from granivorous 
birds. On looking, however, to the great divisions 
in every class of zoology, we see that no characters 
ean be more natural than such as separate destroy- 
ing from harmless animals among quadrupeds. The 
most ferocious genera are brought together in 
the order Fere, composed entirely of the beasts of 
prey : here we have the lion, the tiger, and all the 
races of leopards, panthers, and cats ; together with 
the weasels, polecats, and those minor blood-sucking 
quadrupeds, as destructive and sanguinary towards 
the smaller animals, as the former are to the larger. 
These find their representatives in the rapacious 
order of birds ; and in both, the nature of their food 
is at once explained by the construction oi their 
mouth: the teeth of one, and the notched bill of the 
other, being especially adapted for tearing flesh. 
Extending this analogy to the insect world (which, 
by the way, has never yet been done correctly), we 
find the great majority of Aptera, or the wingless 
orders,—as the spiders, scorpions, crabs, &c.— 
feeding in like manner upon other insects, and living 
only upon the blood and flesh of their victims. So 
strongly, infeed, has nature preserved this distinction 
between her types of evil and of good, or, to drop 
metaphor, between noxious and innoxious animals, 
that not only are these the essential distinctions of 
her primary groups in every class, but they can be 
s 3 
