LINNZAN SYSTEM. 141 
or quadrupeds ; 2. Aves, or birds; 3. Amphibia, or 
reptiles ; 4. Pisces, or fish ; 5. Jnsecta, or insects ; and 
6. Vermes, or worms. These he distinguishes in the 
following manner : — 
Cuv. M‘Leay. 
I 
Heart with ‘two auricles Viviparous. Mammalia, Ib. Ib. 
and two ventricles ; blood ) Oviparous. Birds. Ib. Ib. 
‘aie St 4 f REPTILIA 
Heart with one auricle and Lungs voluntary. Amphibia. Ib. j AMPHIBIA. 
one ventricle ; blood cold, ) External gills. Fishes. Ib. Ib. 
red - - - 
{ Furnished with } 
cl api a ae | \antennes Insects. Ib. 
nd Bile Sera ies cold, * Furnished with Mcxuusca. 
a a be “ke eee co’, | antenne with © Worms. ACRITA. 
ae L_ tentacula. RaDIATA. | 
(193.) Considering the period when this scheme was 
drawn up, we must allow it the credit of being much 
more definite and practically useful than any of those 
which it supplanted: we allude more especially to the 
two latter divisions, in reference to the object which our 
author had in view, namely, the ready determination of 
the name of a species. ‘The whole is confessedly an 
artificial system ; and the author has obviously made the 
class Vermes a general receptacle for all those invertebrat- 
ed animals which could not be classed with any other 
class. When, therefore, we express surprise that a genius 
like Linneus could have brought together animals so 
totally different in their nervous system, their internal 
anatomy, and their external organisation, we must re.. 
member the remoteness of the period at which he wrote, 
the state of knowledge at the time, and the mistakes, 
equally glaring, which from the same causes his predeces- 
sors,even Aristotle himself, have equally committed. Be- 
sides, it must be confessed that the Linnean Vermes, not« 
withstanding our increased knowledge of their true nature, 
have so many external points of general similitude, that 
we can feel no surprise at the whole being considered as 
one group: Nor is it, in fact, at all improbable that they 
actually are so. For if, as there is good reason to sup~ 
pose, reasoning analogically, the modern classes of Acrita, 
Mollusca, and Radiata form a circle of their own, then 
