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 zoology 

 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 is in 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. 



