PREFACE. V 



such relative quantities, as to leave no residuum of facts unex- 

 plained ; and, thereby, the necessity is obviated, of any refer- 

 ence to such metaphysical and unscientific entities, as " innate 

 tendency," and others, such as Darwin employs. 



The result, moreover, of this mode of distribution of the 

 same facts under the same set of principles, is (as the author 

 conceives) to prove, unmistakably, the immutability of each 

 species. 



The advantage of the plan herein pursued, is, that no con- 

 troversy, whatever, can reasonably arise, respecting either the 

 validity of the facts employed, or the legitimacy of the princi- 

 ples assumed. The issue is narrowed down to the mere ques- 

 tions, of the soundness of the mode in which the facts are 

 distributed, and of the significance of the results of such a 

 manner of apportionment. 



To avoid the appearance of egotism, and the circumlocution 

 by which such effect might have been avoided, the plural pro- 

 noun has been used, instead of the more obtrusive I. 



T. WARREN O'NEILL. 



Philadelphia, December 20, 1879. 



