Skeletal morphology seems to be controlled not only by evolutionary heritage and necessities of adaptation to specific environments, but also by morphogenetic programs which often appear as non-adaptational elements of low taxonomic significance. Constructional morphology tries to find out how the three groups of factors are correlated in a given form. This article is the first of a series of papers in which these principles will be applied to different groups of organisms.

Einleitende Bemerkungen zu einer Artikelserie, in der neben der historisch-phylogenetischen und ökologisch-adaptiven Bedingtheit fossiler und fossilisierbarer Formen auch allgemeinere morphologische «Lizenzen» beleuchtet werden sollen.