[On the Origin of Species by Charles Darwin]@TWC D-Link bookOn the Origin of Species CHAPTER II 20/29  
 The whole subject, however, treated as it necessarily here  is with much brevity, is rather perplexing, and allusions cannot be  avoided to the "struggle for existence," "divergence of character," and  other questions, hereafter to be discussed.       Alphonse de Candolle and others have shown that plants which have  very wide ranges generally present varieties; and this might have been  expected, as they are exposed to diverse physical conditions, and as  they come into competition (which, as we shall hereafter see, is a far  more important circumstance) with different sets of organic beings. 
  But  my tables further show that, in any limited country, the species which  are the most common, that is abound most in individuals, and the species  which are most widely diffused within their own country (and this is a  different consideration from wide range, and to a certain extent from  commonness), oftenest give rise to varieties sufficiently well-marked to  have been recorded in botanical works. 
  Hence it is the most flourishing,  or, as they may be called, the dominant species--those which range  widely, are the most diffused in their own country, and are the most  numerous in individuals--which oftenest produce well-marked varieties,  or, as I consider them, incipient species. 
  And this, perhaps, might have  been anticipated; for, as varieties, in order to become in any degree  permanent, necessarily have to struggle with the other inhabitants of  the country, the species which are already dominant will be the most  likely to yield offspring, which, though in some slight degree modified,  still inherit those advantages that enabled their parents to become  dominant over their compatriots. 
  In these remarks on predominence, it  should be understood that reference is made only to the forms which come  into competition with each other, and more especially to the members  of the same genus or class having nearly similar habits of life. 
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