ADVANTAGES OF ARTIFICIAL SYSTEMS. 195 
such writers as divide every group into two; the one 
having positive, the other negative characters. These, 
indeed, are so simple, that the most illiterate can 
understand them; for we have only to see what an 
animal has, and what it has not, to find it out and 
determine its name. Such methods of arrangement, 
as might have been expected, violate the series of 
nature at almost every step; but this, as before 
observed, is of no sort of consequence in a really 
artificial system, where the primary object is to 
arrange animals, as nearly as it is possible, on the 
same plan as words are placed in a dictionary. 
(133.) The disadvantages, however, of all such 
methods more than counterbalance the facilities 
they appear to offer. In the first place, they must 
necessarily disregard the order of nature, which it 
is the chief object of this science to discover and to 
unfold. As their perfection consists in their abso- 
luteness, they must separate into widely different 
groups, animals which are not only of the same 
genus, but actually of the same species. For in- 
stance, no arrangement of insects appears more 
simple, and even in some respects more natural, than 
that which divides them into such as have wings, and 
such as have none. Yet if this plan is so rigorously 
acted upon, as to render, it a correct guide or index 
to the nomenclature of insects, we must place the 
female glowworm in one division, and the male in 
the other; the first being without wings, while the 
latter has four, two of which form cases for the pro- 
tection of the others. The sexes of several moths, 
where the same singular differences are found, must, 
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