PAUCITY OF ITS KNOWN LAWS. 207 
a clue to their developement; or he must begin by 
assuming as true, those laws which have been de- 
monstrated by others, and proceed at once to verify 
them in the groups he is about to investigate. 
(142.) So little had the philosophy of zoclogy 
been attended to by those who, nevertheless, in 
other respects, have been the greatest benefactors 
to the science, that it is only within the last fifteen 
years we can date the commencement of such en- 
quiries. It was then that the first efforts were made 
to reduce it to an inductive science, to be pro- 
secuted by the same method of enquiry which had 
long been employed in other departments of natural 
philosophy. Hence it is, that this science is based 
upon fewer known and acknowledged truths than 
any other. So strong has been the force of prejudice 
in favour of artificial methods, and so little disposed 
are the naturalists of the old school to quit the 
beaten path they hitherto traversed, that if it were 
asked, what were the number of general laws or in- 
ductive generalisations of the highest order, at 
present admitted in this science, we should be ob- 
liged to confess that only one, as yet, has been ex- 
tensively verified. This: one, however, is of the 
most comprehensive nature; since it regards the 
chain of being, or the order of succession, in the 
forms of nature which we are at present discussing. 
The law in question is this ; — That the progression - 
of every natural series isin a circle; so that, strictly 
speaking, it possesses neither a definite beginning 
nor a definite end; the two extremes blending 
into each other so harmoniously, that, when united, 
no marked interval of separation is discovered. 
