Page - 70 - in The Origin of Species

70 ORIGIN OF SPECIES which have very v^^ide ranges generally present varieties ; and this might have been expected, as they are exposed to diverse physical conditions, and as they come into competi- tion (which, as we shall hereafter see, is an equally or 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 considera- tion from wide range, and to a certain extent from com- monness), 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 varie- ties, or, as I consider them, incipient species. And this, per- haps, 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 spe- cies which are already dominant will be the most likely to yield offspring, which, though in some slight degree modi- fied, still inherit those advantages that enabled their parents to become dominant over their compatriots. In these re- marks on predominance, it should be understood that refer- ence 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. With respect to the number of individuals or commonness of species, the comparison of course relates only to the members of the same group. One of the higher plants may be said to be dominant if it be more numerous in individuals and more widely diffused than the other plants of the same country, which live under nearly the same conditions. A plant of this kind is not the less dominant because some conferva inhabiting the water or some parasitic fungus is infinitely more numerous in individuals, and more widely diffused. But if the conferva or parasitic fungus exceeds its allies in the above respects, it will then be dominant within its own class.