r4 THE ORIGIN OF SPECIES 



CHAPTER II 



VARIATION UNDER NATURE 



Tariabilit}' — Individual differences — Doubtful species — Wide ranging, much 

 diffused, and common species, vary most — Species of the larger genera 

 in each country vary more frequently than the species of the smaller 

 genera — Many of the species of the larger genera resemble varieties in 

 being very closely, but unequally, related to each other, and in having 

 restricted ranges 



Variability 



BEFORE applying the principles arrived at in the 

 last chapter to organic beings in a state of nature, 

 we must briefly discuss whether these latter are 

 subject to any variation. To treat this subject properly, 

 a long catalogue of dry facts ought to be given; but 

 these I shall reserve for a future work. Nor shall I 

 here discuss the various definitions which have been 

 given of the term species. No one definition has satis- 

 fied all naturalists; yet every naturalist knows vaguely 

 what he means when he speaks of a species. Generally 

 the term includes the unknown element of a distinct act 

 of creation. The term "variety" is almost equally diffi- 

 cult to define; but here community of descent is almost 

 universally implied, though it can rarely be proved. We 

 have also what are called monstrosities; but they gradu- 

 ate into varieties. By a monstrosity I presume is meant 

 some considerable deviation of structure, generally injuri- 

 ous, or not useful to the species. Some authors use the 

 term "variation" in a technical sense, as implying a 



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