THE ANIMAL KINGDOM. 29 



The natural Divifion of Animals into Gaffes, may be formed from a knowledge of 

 the Internal Stru&ure : 



r A heart with two auricles C Viviparous. CI. 1. Mammalia. 



1. ■? 1 and two ventricles ; < 



(^Warm and red blood: £ Oviparous. CI. 2. Birds, 



CA heart with one auricle C Voluntary lungs. CI. 3. Amphibia. 



2. ■< and one ventricle ; < 



£ Cold red blood * : (^External gills. CI. 4. Fifhes. 



C A heart with one auricle C Having antennae. CI. 5. InfeEls. 



3. < and one ventricle ; < 



C.Cold colourlefs fanies : £ Having tentacula. CI. 6. Worms. 



CHARACTERS 



* Haller, Element. Phyfwl. i. 305. 307. informs us, that in all the cold blooded animals which he had 

 diffedted, he uniformly found the heart to have but one auricle and one ventricle ; it is therefore furpri- 

 fing that HafTelquift, Itin. Palefl. 293, fhould afcribe two of each to the crocodile, more efpecially as 

 Borichius, Herm. Sap. Egypt. 276, had before declared its heart to have only one of each. — Lin, 



