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 
