Note 61 — THE INDIVIDUAL ORGANISM WITH REGARD TO FORM AND METABOLISM (continued 2)

One might object here that in a piece of a Tubularia stem, for instance, the tissues are in direct contact with the sea-water at the two points of the wounds only, and that at these very points a stimulus might be set up—say by a process of diffusion—which gradually decreases in intensity on its way inward. And a similar argument might apply to the small but whole blastula of Echinus, and to all other cases. But, in the first place, stimuli which only differ in intensity could hardly call forth the typical and typically localised single features realised in differentiation. On the other hand—and this will overthrow such an hypothesis completely—the dependence of the single localised effects in every case on the absolute size of the fragment or piece chosen for restoration renders quite impossible the assumption that all the singularities in the differentiation of the harmonious systems might be called forth by single stimuli originating in two fixed places in an independent way. These would never result in any “harmonious,” any proportionate structure, but a structure of the “normal” proportionality and size at its two ends and non-existent in the middle!