246 FIRST PRINCIPLES OF NATURAL CLASSIFICATION. 
that even among insects, where no other power is pos- 
sessed but that of causing annoyance or temporary 
pain, we find, in the sub-typical order of the Annulosa 
(Aptera Lin. y: the different race of scorpions, Acari, 
spiders, and all those repulsive insects, whose very aspect 
is forbidding, and whose bite or sting: is often capable of 
inflicting serious bodily injury. If, again, we look to 
the sub-typical groups of quadrupeds and of birds, this 
principle of evil is developed in the highest degree ; 
both are armed with powerful talons, both live on 
slaughtered victims, and both are gloomy, unsocial, and 
untameable. The formidable toothed bill, which so 
strikingly distinguishes rapacious birds, will be found 
in every group which represents them in the entire or- 
der of perchers, and these groups amount to more than 
one hundred. Even in the genus Sylvicola, among the 
warblers, the bill of the sub-typical group represents in 
miniature that of the rapacious order, the peculiar cha- 
racter of which consists in a conspicuous tooth or notch, 
placed more remote from the end of the upper man- 
dible than it is in all other types. Even in the smaller 
sub-typical groups of larger circles, which are themselves 
typical, this extraordinary characteristic is manifested, 
although in a much slighter degree. Take, for instance, 
the American group of monkeys (Cebide@ Sw.) which 
belong to the typical order of Quadrumanes ; of that 
circle it is the sub-typical group, and we accordingly 
find, that while the family of true apes (Simiad@) live 
in a state of nature upon vegetable diet alone, the Ce- 
bide are partially carnivorous, and that many prowl about 
to destroy life by feeding upon insects, and even small 
birds. 
(306.) The above are sufficient demonstrations of 
this law in larger groups; but as the best test of a 
theory is to follow it down into the lowest form of ana- 
lysis, we will now see in what manner it is exemplified 
in species of the same genus. Let us first look to that 
of Bos, where we have the ox and the bison actually 
followi1:g each other in close affinity, and yet no two 
