Note 54 — THE INDIVIDUAL ORGANISM WITH REGARD TO FORM AND METABOLISM (continued 2)

At any given time only the absolute size of the regenerated part is greater in animals which are well fed; the degree of differentiation is the same in all. Zeleny has found that, if all five arms of a starfish are removed, each one of them will regenerate more material in a given time than it would have done if it alone had been removed. But these differences also only relate to absolute size and not to the degree of differentiation. They possibly may be due in fact to conditions of nourishment, but even here other explanations seems possible (Zeleny, Journ. exp. Zool. 2, 1905).