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THE AMERICAN JOURNAL OF SOCIOLOGY
vidual free-will, the life of the organism considered as having its first cause independent within the organism itself. Weismann recognized, however, that in the above example of the tree frog it is a question of adaptation. Why, then, contend that the environment in connection with the organism is not a modifying condition to which the tree frog adapts itself, as well as that the constitution of the latter is a condition of this same modification? 1 After that, in another of his essays, Weismann comes clearly to concede that the external environment may be regarded as the indirect cause of structural modifications :
If among moths the outer side is gray like the wall upon which it sleeps during the day, and if among butterflies the under sides of the wings drawn back in repose possess a protective coloration, that is not at all the direct result of the influence of the wall ; but if it is brought about naturally, it may
be indirectly the result of the wall We ought not always to be forced
to return to this A B C of our knowledge concerning the causes of transmu- tation If Detmer had taken this precaution, he would have guarded
against adding this phrase as a resume" of the experiments which he has invoked in vegetable physiology, viz.: " It is possible in certain cases, as we have seen, to modify by experimentation the anatomical structure of par- ticular organs of plants." In this case, there is undoubtedly a relation between this modification and the external influences. These latter act as a cause. The anatomical transformation of the elements of the plant is the result of this cause. A little more logic would have guarded him against this, for his conclusion is due solely to confounding the real cause of the phenomenon with one of the conditions in favor of which it may be produced.
Here then is a new distinction, that between the real cause of a phenomenon and the condition without which the phenom- enon could never be produced. The latter is not a real cause. Let us ask: Are not the causes of a phenomenon the conditions which in a constant and necessary manner accompany its pro- duction ? The tendency of Weismann to introduce the methods 'of formal logic into the natural sciences is most deplorable.
Nevertheless, Weismann, little at ease in his casuistry, adds anew his former distinction : "We have here to do with adaptation and not at all with the result of direct action ; " with adaptation, that is to say, with the processus of selection based upon general variability. What does this mean, if not that the
1 WEISMANN, Des prttendues preuves botaniques de Vhe're'dite dts caracteres acquis.
