LINNJBAN SYSTEM. 141 



or quadrupeds ; 2. Aves, or birds ; 3. Amphibia, or 

 reptiles ; 4. Pisces, or fish ; 5. Insecta, or insects ; and 

 6. Vermes, or worms. These he distinguishes in the 

 following manner : 



Cuv. M'Leay. 



i. r 



Heart with two auricles A Viviparous. Mammalia. Ib. Ib. 



and two ventricles ; blood y Oviparous. Birds. Ib. Ib. 



warm, red - - C 



Heart with o'ne auricle and ^Lungs voluntary. Amphibia. Ib. [ JjJ*, 



one ventricle; blood cold,) External gills. Fishes. Ib. Ib. 



red C 



TTT f Furnished with 7 T * <- TK 



HI. anfonn C l ns 6CtS. Ib. 



Heart with one auricle and ,' -"' "f ' : fh = 

 no ventricle ; sanies cold^ g {J Worms< 



t whlte L tentacula. J 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 Linnaeus could have brought together animals so 

 totaUy 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 Linnaean 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 



