Classification of Animals. 553 



induced to devote more space to the developement of the leading 

 principles of this system, than we should otherwise have done, on 

 many important accounts. First, Because it is unquestionably the 

 first which clearly defined any one philosophic principle of classifi- 

 cation, so that, strictly speaking, we must date the first partial de- 

 velopement of natural arrangement from the publication of the 

 Horse Entomologicas. Lamarck, it is true, traced the outlines of 

 the circle without knowing that he had done so ; while Mr M'Leay, 

 by a totally different process of investigation, arrived at the same 

 general result, but with this difference ; — that he discovered pro- 

 perties which belonged to this series of universal prevalence in na- 

 tural groups, and he determined several of those laws which regu- 

 lated the variation of animals ; a process of induction which hereto- 

 fore had never been dreamed of. These discoveries let in a flood of 

 light on the study of nature, and converted that whicli had been a 

 science of observation into one of the deepest philosophy." — The 

 Sy sterna Mycologiaim of M. Fries is afterwards noticed, which is bas- 

 ed upon the three great principles of natural classification announced 

 a little previously by Mr M'Leay, but of which fact this eminent 

 botanist was altogether ignorant when he made the same discoveries 

 during his investigation of a group of the vegetable kingdom. The 

 only point of difference between them is in the determinate number 

 of their groups, those of M'Leay being five, while those of M. 

 Fries are apparently four, we say only apparently, for they are in 

 reality five, as he confesses that his centrum or typical group is al- 

 ways divisible into two series. Modifications which Mr M'Leay 

 made in his system are afterwards noticed, as well as the views 

 of other writers in regard to natural arrangement ; and the chap- 

 ter concludes with some general remarks which may, we hope, 

 prevent in future any of those deviations from the true principles 

 upon which the circular theory is established, and which can only 

 tend to bring it into disrepute. Having taken a review of the va- 

 rious systems, artificial as well as natural, which have appeared, he 

 proceeds, in the third part of the volume, to lay before his readers 

 the result of his own researches on the first principles of the natu- 

 ral system, which are embodied in the following five propositions : — 



1. That every natural series of beings, in its progress from a 

 given point, either actually returns, or evinces a tendency to return 

 again to that point, thereby forming a circle. 



2. The primary circular divisions of every group are three ac- 

 tually, or five apparently. 



