MIXED SYSTEMS. 197 
much time in becoming acquainted with a super- 
ficial classification, as would have sufficed for the 
acquirement of a sound one. 
(134.) The glaring violations of nature which 
result from a strictly artificial system, have been 
felt so forcibly by nearly all the best systematic 
writers, that they have endeavoured to unite facility 
of research with some attention to the order of 
nature; hence the origin of mixed systems, such 
as that of the Régne Animal of Cuvier, and the 
Genera Insectorum of Latreille. Arrangements of 
this description have been, and still are, highly 
useful; inasmuch as they bring together the scat- 
tered fragments of the natural series, disjointed and 
severed by artificial methods of arrangement. Yet 
they are not so useful to the searcher after species, 
because a wider latitude is given to the definitions ; 
nor can they be considered as built upon philosophic 
principles, for they commence upon no universal 
and acknowledged truths of natural classification. 
They frequently bring together natural groups ; but 
after proceeding awhile in the evident order of 
nature, they suddenly stop, and enter upon another 
portion of their subject, as if it had no connection 
whatever with that which they had just left. With 
this they go on in some regularity ; but soon another 
interruption is apparent, another gap is to be leaped, 
and another series is begun upon, as if it had no- 
thing to do with the last. These systems, which ex- 
hibit nature, not as a whole, but as pieces, may be 
compared to fragments of a chain, each composed 
of an unequal number of links, which as far as they 
extend are perfect, but whose two extremities show 
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