OTHER NATURAL SYSTEMS. 291 
thought to be effected by Barbicornes (an Erycinian 
butterfly) and Lasiocampa. 
(271.) Without entering more into the details of 
the various hypotheses last mentioned, it appears ex- 
pedient, in this place, to recall the mind of the naturalist 
to the essence of those remarks which have been given 
more fully in another place*, and which are applicable 
alike to all theories which set out with the admission of 
the first law of natural classification — the circularity of 
groups. It is evidently easy, for it requires no great 
ingenuity, to divide a group into three, four, five, seven, 
or any other given number ; but before such a division 
can be called ‘‘ natural,” there are certain peremptory 
conditions, which, in the present state of science, must 
be complied with. The first of these is a demonstra- 
tion of the theoretic principle upon which the author 
builds his system. He is not merely to assert, but he is 
to prove, that his “‘ natural” orders, — or whatever other 
denomination he affixes to his groups,—are each of 
them circles of affinity. To profess a belief in the cir< 
cular system, and yet set at nought its practical exem-~ 
plification, is childish ; and, but for its inconstancy, 
would injure science, by despising inductive reasoning. 
An author who fixes upon any definite number, for the 
division of an entomological group, should first prove 
that the same number also exists in the ornithological 
and all other zoological circlest, otherwise he tacitly 
admits the monstrous and exploded supposition that 
there is no uniformity of plan in the creation beyond 
circles. If, therefore, the annulose kingdom, in its 
primary divisions, is resolvable into seven circles, so 
also must be the vertebrated kingdom: otherwise we 
exhibit insects as created upon one plan, birds upon a 
second, and quadrupeds (probably) upon a third. It 
is really most disheartening to find naturalists (especially 
* Preliminary Discourse on Nat. Hist. p. 225. 
+ The ingenious author of Sphinx Vespiformis, however, promises to do 
this in a separate essay, already (1832) in a state of forwardness. We 
hope this will soon appear. If he is successful in establishing a more har- 
monious theory than that which is already known, we shall be the first to 
proclaim the fact, 
“ 
