Abstract

Heat sensitive pit organs in different species of snakes show various shapes. The relation between form characters and functions were analysed by means of two different research programs. This paper presents the methodological steps involved in these research programs. The first approach is called a qualitative explanation because it connects experimental data by means of qualitative statements in order to give a functional morphological explanation for the construction of the pits in respect to the behaviour of the snake. The second approach is called a quantitative explanation because the core of the explanation is a mathematical model which in its consequences explaines the construction of the pits in respect to image formation.