Now, I beg the reader again to remember that all species of animals and plants are variable, and possess the capability of adapting themselves to different places or to local relations. The varieties or races of each species, according to the laws of adaptation, deviate all the more from the original primary species, the greater the difference of the new conditions to which they adapt themselves. If we imagine these varieties—which have proceeded from a common primary form—to be disposed in the shape of a branching, radiating bunch, then those varieties will be best able to exist side by side and propagate which are most distant from one another, which stand at the ends of the series, or at the opposite sides of the bunch. Those forms, on the other hand, occupying a middle position—presenting a state of transition—have the most difficult position in the struggle for life. The necessaries of life differ most in the two extremes, in the varieties most distant from one another, and consequently these will get into the least serious conflict with one another in the general struggle for life. But the intermediate forms, which have deviated less from the original primary form, require nearly the same necessaries of life as the original form, and therefore, in competing for them, they will have to struggle most with, and be most seriously threatened by, its members. Consequently, when numerous varieties of a species live side by side on the same spot of the earth, the extremes, or those forms deviating most from one another, can much more easily continue to exist beside one another than the intermediate forms which have to struggle with each of the different extremes. The intermediate forms will not be able to resist, for any length of time, the hostile influences which the extreme forms victoriously overcome. These alone maintain and propagate themselves, and at length cease to be any longer connected with the original primary species through intermediate forms of transition. Thus arise “good species” out of varieties. Thus, then, the struggle for life necessarily favours the general divergence of organic forms, that is, the constant tendency of organisms to form new species. This fact does not rest upon any mystic quality, or upon an unknown formative tendency, but upon the interaction of Inheritance and Adaptation in the struggle for life. As the intermediate forms, that is, the individuals in a state of transition, of the varieties of every species die out and become extinct, the process of divergence constantly goes further, and from the extremes forms develop which we distinguish as new species.