The paper outlines the contours of an organizational perspective on extended inheritance. Based on theoretical studies about biological organization and extended physiology, this perspective allows for the conception of extended biological legacies while keeping a theoretically indispensable distinction between biological systems and their environment. In this context, the line of demarcation between these systems and their surroundings is modelled on an organizational criterion and on the related conceptual distinction between organizational constraints, whose specific role is to harness flows of matter (...) and energy across generations of composite biological systems, and resources exploited by those systems. Biological legacies are restricted to persisting constitutive elements responsible for the reoccurrence of organizational constraints in a given environment. The case of symbiotic transmission is presented as a paradigmatic system illustrating the main proposed conceptual clarifications. (shrink)