ANIMALS. 441 



One fault more, in almost all these systematic writers, and 

 that which leads me to the subject of the present chapter, is, 

 tliat seeing the necessity of methodical distribution in some jiarts 

 of nature, tliey have introduced it into all. Finding the utility 

 of arranging plants, birds, or insects, they have arranged quad- 

 rupeds also with the same assiduity ; and although the number 

 of these is so few as not to exceed two hundred,' they have 

 darkened the subject with distinctions and divisions, which only 

 serve to puzzle and perplex. All method is only useful in giv- 

 ing perspicuity, where the subject is either dark or coj)ious ; 

 but with regard to quadrupeds, the number is but few ; many of 

 them we are well acquainted with by habit ; and the rest may 

 very readily be known, without any method. In treating of 

 Kuch, therefore, it would be useless to confound the reader with 

 a multiplicity of divisions ; as quadrupeds are conspicuous 

 enough to obtain the second rank in nature, it becomes us to be 

 acquainted with, at least, the names of them all. However, as 

 there are naturalists who have gaitied a name from the excel- 

 lence of their methods in classing these animals, some readers 

 may desire to have a knowledge of what has been laboriously 

 invented for their instruction. I will just take leave, therefore, 

 to mention the most applauded methods of classing animals, as 

 adopted by Ray, Klein, and Liimajus ; for it often happens, 

 that the terms which have been long used in a science, though 

 frivolous, become, by prescription, a i)art of the science itself.* 



Ray, after Aristotle, divides all animals into two kinds ; those 

 which have blood, and those which are bloodless. In the Ian i 

 class, he places all the insect tribes. The former he divides 

 into such as breathe through the lungs, and such as breathe 

 through gills ; these last comprehend the fishes. In those 

 which breathe through the lungs, some have the heart composed 

 of two ventricles, and some have it of one. Of the last are all 

 animals of the cetaceous kind, all oviparous quadrupeds, and 

 serpents. Of those that have two ventricles, some are ovipa- 



1 III Dr Shaw's Ofnpral Zoolof^y, tho number of quadrupeds, not includinff 

 the retaccoua and seal tribes, amount to five hundred and twelve, besidse 

 their varieties. 



* In the appendix to tliis work, the reader will find a view of the various 

 flassifieations of animals, particularly of the Cuvierian or natural system ot 

 Zoology. 



