INTRODUCTION. XXV 



When so many eminent men form different conclusions from the same premises, 

 we may rest assured that there is something in the subject of their lucubrations 

 that admits of hesitation, and justifies variety of opinions ; and this is clearly the 

 case with respect to the arrangement of natural objects ; for whether we consider 

 the productions of our globe, in all their affinities, as best represented by a branch- 

 ing tree, a net, or a sphere formed of an infinity of larger and smaller orbits, 

 connected on every side, and placed ad infinitum wheel within wheel ; if we set 

 ourselves to arrange and describe upon paper the individuals composing any de- 

 partment of the three kingdoms, we shall find that it is above us either to conceive 

 or delineate it so as to maintain all its connections undisturbed and unbroken. 

 We must do it in a series, which can only be a series of mutilations and disloca- 

 tions. It will be like cutting oif every branch and twig of the tree to place them 

 end to end ; like tearing up the net to place all the meshes one after the other ; 

 like blowing up the whole sphere, and unravelling, as it were, all its orbits great 

 and small, to make a continuous thread of them. So that it is a hopeless case to 

 attempt an arrangement according with nature in all its parts; vain man, with all 

 his boasted powers of intellect, cannot conceive, much less utter and embody it. 

 All that he can accomplish is to give some general idea of it, and to describe some 

 fractions of it. He can also attend to the composition of his groups, and keep 

 those together that are really related ; but as to conterminous groups, he will often 

 be at a loss which is nearest to the one in question, for from different parts of the 

 same group, a variety of others will often branch off in different directions. 



In the following pages, therefore, profiting by the labours of my predecessors, 

 I have sometimes followed one and sometimes another, according as they appeared 

 to me best to have interpreted nature, and sometimes, where it seemed expedient, 

 I have entered new paths in my arrangement; it has been my endeavour principally 

 to make my groups as near to nature as possible, but with regard to the series and 

 concatenations of them, for the reasons above assigned, it was not possible to place 

 them on paper as they are inscribed, by the Great Author of nature in her pages. 



