Abstract

Comparative biological morphology, incorporating the study of active reaction, is contrasted with genetics as the study of passive mutation. Geneticists investigate anatomical characters, never anatomical constructions, which are capable of reorganization when the biological-morphological equilibrium of the organism has been disturbed. The anatomy of Opisthocomus cristatus and Stringops habroptilus demonstrate that three successive disturbances in the bio-morphological equilibrium are reacted to purposively by anatomical reconstruction. These reactions are no accidental mutations, but are anatomical reactions, related to, and affecting, the organism as a whole. In sharp contrast to such anatomical reaction, resulting, during phylogeny, in reorganization, are the “technics” [i.e., mechanistic bases] of individual development. The hereditary process is, like every physiological or embryological process, a fixed mechanism, which remains constant until an active reaction leads to reconstruction and at the same time an appropriate change of the mechanisms. The remolding of species is therefore no passive, “technical” process, but a creative act of the organisms themselves. [Original English abstract; not translated.]