204 STUDY OF NATURAL HISTORY. 



mine which is the natural series of the groups now 

 before me ? Here, then, commences the philosophy 

 of the science. For we have either to determine 

 these questions by a long process of inductive gene- 

 ralisations, which will probably occupy years of 

 incessant study ; or we must have recourse to the 

 experience of others, and proceed to verify, by the 

 subjects before us, those general conclusions which 

 others have arrived at upon the points in question. 

 This, therefore, will be the place for giving to each 

 of these general conclusions some consideration. , 



(139.) It was long the opinion of philosophers, 

 that the chain of being, or, in other words, the 

 order of nature, was simple. So that, between man, 

 and the minutest animalcule invisible to the naked 

 eye, there was an innumerable multitude of or- 

 ganised beings descending imperceptibly in the 

 scale, and forming a simple continuous series, like 

 the links of a chain ; the first of which was very 

 large, and the latter very small, the intervening 

 ones gradually lessening as they approached the 

 lowest extremity. Now, this theory has long since 

 been abandoned ; because, although we can select 

 from the animal world a series which will answer to 

 such a theory, we should still be obliged to omit 

 nearly one third of the animals already known, 

 which will not, by any possible contrivance, fall into 

 a linear series, and which consequently demonstrates 

 its fallacy. The very instance we have just given, 

 makes this apparent to the most inexperienced stu- 

 dent. If the chain of being had been simple and 

 linear, he would have had no difficulty in placing 

 his insects in such a series ; and one would have 



