Introduction

Abstract

No organ system can be completely understood if it is considered isolated from all others. By the same token, the interrelationship in structure and function within and among organ systems can be used in order to validate assumptions concerning one system based upon information from another (Cuvier 1812). Furthermore, most anatomical differences between related organisms can be explained in terms of allometric modifications of structural entities already present in their common ancestor (Thompson 1951). These two principles — the structural and functional integrity of the organism and the dependence of any given structure upon the phylogenetic heritage of the organism — are cornerstones of comparative anatomy. Traditionally, the latter has been emphasized and employed to determine systematic relationships (Hennig 1966). In the present work such previously determined relationships among major groups will be tentatively assumed correct. Within this framework, the structurefunction relationship will be examined in detail in the respiratory system of two species of lizard in which the lung structure is fundamentally different. These correlations will then be extended to other organ systems, including the locomotor system, in these and other species. Finally speculation regarding the possible structure of lungs in certain extinct species will be risked.

«Tout être organisé forme un ensemble, un système unique et clos, dont toutes les parties se correspondent mutuellement, et concourent à la même action définitive par une réaction réciproque. Aucune de ces parties ne peut changer sans que les autres changent aussi; et par conséquent chacune d’elles, prise séparément, indique et donne toute les autres.»

Cuvier (1812)