NATURAL SYSTEMS. MACLEAy's. 213 



be applied. Such are the fundamental principles of 

 classification contained in the Hora EntomologiccB ; the 

 modifications which they subsequently received from its 

 author, wiU be presently stated. 



(266.) The system of M. Fries is the next in order 

 of succession ; for, although it was applied by this dis- 

 tinguished botanist only to a natural group in the 

 vegetable kingdom, its principles are too important not 

 to be equally deserving the attention of the zoologist. 

 It is very remarkable, that this consummate botanist, 

 totally ignorant of the previous publication of the HorcB 

 Entomologicce, should have detected the same principles 

 of circular affinities therein developed, and should have 

 illustrated them, by analyses, much more fully. Yet, 

 although these naturalists agree in considering the cir- 

 cularity of groups to be the first principle of the natural 

 system, they differ in the determinate number of their 

 groups ; those of Mr. jMacLeay being, in fact, ten (or, ac- 

 cording to his subsequent belief, five) ; and those of M. 

 Fries four. It seems, however, that the centrum, or 

 typical group of the German botanist, is always divisi- 

 ble into two series (*frf centrum abit semper in duas 

 series) ; and that each of his series or groups is a circle, 

 appears evident from the following words: — Omnis sectio 

 naturalis circulum per se clausum exhibet, that is, every 

 section, series, or group, forms, of itself, a circle. 

 Hence it follows, that, as one of M. Fries's groups, ac- 

 cording to his own account, is always divisible into two, 

 thus their total number is not four, but five. The dif- 

 ference^ therefore, between this theory and the last is 

 rather nominal than real : for as M. Fries at the same 

 time detected the theory of representation, by which the 

 contents of one circle typified the contents of a neigh- 

 bouring circle, this, of course, led him clearly to un- 

 derstand and to define the difi^erence between analogy 

 and affinity. It is plain, therefore, that the three great 

 principles of natural arrangement given to the public in 

 the first instance by Mr. MacLeay, were also discovered 

 by M. Fries; we say discovered, in contradistinction 



p 3 



