li}2 ON SYSTEMATIC ZOOLOGY. 



of the subject, it results that there are many natural 

 systems^ or rather, that there are many attempts to ex- 

 plain those complicated relations which belong to the 

 natural series. We prefer, in this instance, a compre- 

 hensive definition to a metaphysical one ; because, were 

 we to adopt the latter, we should be compelled to con- 

 sider the system of Mr. Mac Leay artificial, since many 

 properties of natural groups have been since discovered, 

 and several combinations detected_, which were quite - 

 unknown when that system was given to the world. 



CHAP. II. 



EXPOSITION, WITH REMARKS ON THE PRINCIPAL ARTIFICIAI. 



SYSTEMS. ARISTOTLE, WILLUGHBY, LINN^US, CUVIEB. 



PARTIAL SYSTEMS. ILLIGER, VIEILLOT, TEMMINCK, IN OR- 

 NITHOLOGY DE GEER, LATREILLE, CLAIRVILLE, AND LEACH, 



IN ENTOMOLOGY ON BINARY, OR DICHOTOMOUS, SYSTEMS. 



(184.) The advantages and the disadvantages of arti- 

 ficial systems have been already touched upon (178.), 

 and their use explained * ; it remains, therefore, to give 

 the reader a general idea of those systems which have 

 been most celebrated, or most extensively adopted. As 

 artificial systems are capable of endless diversity, so it 

 would be impossible to enumerate, mthin reasonable 

 limits, one half of those which have been already pub- 

 lished; setting aside others, which a very slight ac- 

 quaintance with nature will enable every student to 

 invent. One advantage has certainly attended that de- 

 ference and respect with which — particularly in this 

 country — the writings of the great Swede have always 

 been treated ; for although an implicit deference to the 



* Preliminary Discourse, c. iii. p. 188. 



