Iviii PRELIMINARY SKETCH OF THE 



a real scientific arrangement, and who may be 

 said to have laid the foundation of all subse- 

 quent improvement. 



The Linnaean system is, for the most part, 

 founded on the general arrangement of Ray, 

 just alluded to. In the quadrupeds more espe- 

 cially, Linnaeus has followed Ray; but, un- 

 questionably, his whole system is much more 

 extended and improved. 



Linnaeus has divided the animal kingdom 

 into six classes, founded mainly on the dif- 

 ferences in the respiratory and sanguineous 

 systems : — 



Class I. — Mammalia. All suckle their young; 

 the heart has two ventricles and two auricles ; 

 blood red and warm ; viviparous. 



Class II. — Aves (Birds). Characters as in 

 the former class, except oviparous. 



Class III. — Amphibia (Amphibious Animals). 

 Heart one ventricle and one auricle ; blood red 

 and cold ; respiration voluntary. 



Class IV. — Pisces (Fishes). Heart and blood 

 same as in Amphibia ; respiration by gills. 



Class V. — Insect a (Insects). Heart one ven- 

 tricle, no auricle ; sanies cold, colourless ; an- 

 tennae or feelers. 



Class VI.— Vermes (Worms). Characters 



