The Relationship between Serial and Special Homology and Organic Similarities

Abstract

Concepts of developmental genetics and exptl. embryology simplify rather than complicate the problems of homology. Both serial and special homologies, as well as general homologies, are all expressions of similar developmental forces. The author proposes 3 new types of similarities to replace older concepts of homology; these are to be based on (1) developmental, (2) genetic, and (3) evolutionary similarities. In addition, each of these similarities may be analyzed further into those which are alike in origin (homodynamic, homogenetic, and homophyletic, resp.) and those which are not alike (heterodynamic, etc.).