488 Dr. Falconer on Cuvier's Laws of Correlation, 



of empirical relation in the vegetable kingdom against there 

 being necessary or reciprocal relation in the higher classes of 

 the animal kingdom, if it means anything, is exactly of this 

 character. The truth being, that in both plants and animals 

 there are two kinds of relation between the constituent parts or 

 organs : the one empirical, of which we know the invariable 

 constancy, although, so far as our present knowledge goes, we 

 cannot show the reason ; the other reciprocal, of which we 

 equally know the constancy, and at the same time can demon- 

 strate the necessity. Physiology takes cognizance of both ; and 

 as a general expression of the phsenomena it may be stated, 

 that the 7iecessary relations are more numerous and obviously 

 manifested in the ratio of the higher organization of the Living 

 form. Hence the paramount iuiportance of the principle of 

 reciprocal relation as a guide in mammalian palseontology. 



So far as regards the terms above quoted, in which the 

 supposed refutation of the Cuvierian principle is summed up, 

 rarely in the history of science has confident assertion been put 

 forward, in so grave a case, upon a more erroneous and unsub- 

 stantial foundation. Later palaeontologists are brushed aside 

 with still lighter consideration. They are les moutons que suivent 

 " the compilers, and copiers, and popularizers, and id genus 

 omne." It is some consolation to this pecus ignobile to reflect, 

 that Professor Owen has been among their number. Mr. Huxley 

 holds him up in the s quel, as furnishing a bright example (of 

 which more anon) of enipirical deduction ; but it must be ad- 

 mitted, that the Hunterian Professor's numerous works, and 

 reiterated avowals, somewhat compromise him as a rational cor- 

 relation ist *. 



Let us now consider what was the method actually followed 

 by Cuvier in the determination and restoration of extinct fossil 

 forms. He lirst examined, through every organic detail, a vast 

 number of living forms, derived from every class and order of 

 the Vertebrata, with infinite labour and assiduity, during thirty 

 years. In the s|)irit of pure induction, he ascended from the 

 aggregate of the particular observations to general conclusions ; 

 namely, that certain laws of correlation invariably preside over 

 the organization of animals. He found that these laws were 

 classifiable under two heads: 1st, what he called ?Y//ionfl'Z (i.e. 

 general) laws, wherein the correlation is demonstrable as being 

 necessary and reciprocal throughout the parts, just as the form 

 of a piston must be a reciprocal of the cylinder in which it 



* ]Mv. Owen flies his hawk at a more ambitious qiiany in original re- 

 search ; but it is not too much to expect that he may on some occasion 

 record his jHotest against MammaUan Palaeontology being asserted to rest 

 merely on empirical correlation, in a pithy foot-note. 



