I. Haeckel and His Opponents

From among the ever new forms arising in this way, those will survive which can best maintain the struggle for existence. Forms unequal to the struggle will perish. When out of a possibility of evolution a form develops itself which is specially effective in the battle of competition, then this form will reproduce itself; when that is not the case, it must perish. One sees that here causes operating on the organism from without are entirely eliminated. The reasons why the forms change lie in the germ. And the struggle for existence selects from among the forms coming into existence from the most diverse germ-dispositions those which are the fittest. The special characteristic of an organism does not lead us up to a change which has occurred in its ancestors as its cause, but to a disposition in the germ of that ancestor. Since, therefore, nothing can be effected from outside in the upbuilding of organic forms, it follows that already in the germ of the root-form, from which a race began its development, there must have lain the dispositions for the succeeding generations.