392 THE AMERICAN JOURNAL OF SOCIOLOGY
to the antagonists in a more energetic, and also a more and more precise, fashion than formerly.
The question as it actually presents itself is this : Does the environment act upon the germ in such a way that the acquired characteristics are transmitted by heredity? Let us note that in this term "environment" it is necessary to include even the somatic cell in which the germinal plasm is contained. Here the question is narrowly presented in its irreducible elements. We see the path traversed by science and philosophy since the time of Hippocrates and Herodotus, i. e., during about twenty-five cen- turies.
To this question, as formulated by the most recent biologists, we are able to give with Weismann 1 the following general response:
The aptitude for the existence of organic species does not depend solely upon the internal powers of the species. It depends further upon the rela- tions of the species to the exterior world, and it is here that the necessity for adaptation is found. This adaptation, fixed by heredity, limits their structure and their growth.
This law applies to the human species, and also to the varie- ties of human species. It is not an inflexible and absolute law, but is founded upon the constant relations between the internal structure of the species and race, on the one hand, and their environment, on the other. Setting aside any question of first cause or of finality, this law suffices for the explanation of the sociological phenomena of variation, repetition and imitation, heredity and selection, and consequently of the adaptation of the several societies to their respective environments. Weismann unfortunately, as we shall see, partly loses sight of this relative character.
The general variability of organisms, heredity, natural selec- tion, and, as a consequence, the continual adaptation to the en- vironment and I would add that of the environment to the organisms suffice to explain their form and their evolution. They suffice similarly to explain the most general laws of dis- tribution of the human species and races over the surface of the globe.
1 Essais sur fhtrlditt et la selection naturelle ; La vie el la mart.
