Induction and deduction in morphology

Professor de Wilde's scientific contributions can be divided into two separate areas based on the applied methods: induction and deduction. The first method is used in the investigation of the finger ridge pattern and the second in that of the branching of bloodvessels. It is shown that with induction alternative classifications and explanations remain always possible and that the ultimate choice of the classification depends on supposed biological meanings or practical applicability. In the case of the finger ridge patterns the latter criterion is decisive. With the deductive method a sufficient logical explanation within the boundary conditions can be reached. Alternatives can be presented if the boundary conditions are changed or the functional parameters have to be chosen differently, which is necessary when direct observation (induction) "shows" that other functions are involved. A number of advantages and problematic points in both methods are analysed and their relationship and function in morphology are demonstrated in the mentioned research topics.