142 HISTORY OF 



his family with five claws, there are above a hun- 

 dred. 



Brisson, who has laboured this subject with 

 great accuracy, divides animated nature into nine 

 classes : namely, quadrupeds ; cetaceous animals, 

 or those of the whale kind ; birds ; reptiles, or 

 those of the serpent kind j cartilaginous fishes ; 

 spinous fishes ; shelled animals ; insects ; and 

 worms. He divides the quadrupeds into eighteen 

 orders, and takes their distinctions from the num- 

 ber and form of their teeth. 



But of all those whose systems have been adopt- 

 ed and admired, Linnaeus is the foremost ; as, 

 with a studied brevity, his system comprehends 

 the greatest variety in the smallest space. 



According to him, the first distinction of ani- 

 mals is to be taken from their internal structure. 

 Some have the heart with two ventricles, and hot 

 red blood j namely, quadrupeds and birds. The 

 quadrupeds are viviparous, and the birds ovipar- 

 ous. 



Some have the heart with only one ventricle, 

 and cold red blood ; namely, amphibia and fishes. 

 The amphibia are furnished with lungs ; the fishes 

 with gills. 



Some have the heart with one ventricle, and 

 cold white serum ; namely, insects and worms : 

 the insects have feelers ; and the worms holders. 



The distinctions of quadrupeds, or animals with 

 paps, as he calls them, are taken from their teeth. 

 He divides them into seven orders, to which he 

 gives names that are not easy of translation : Pri- 

 mates, or principals, with four cutting teeth in 



