Aims of this Study

Abstract

The aims of this study can be summarized as follows:

• 1 First of all, to show applicability of the staging and ageing method to all mammals. To point out the advantage of this method in the processing and evaluation of embryological materials, which are many years old in some cases.

• 2 To show the way of evaluating, by means of this method, undated embryological material on a much higher qualitative level, thus making it possible to compare the results obtained with data on other mammal species and/or groups and facilitating the formulation of evolutionary conclusions.

• 3 Including the time coordinate in the so far untimed sequence of developmental events and steps can clarify the rate and consecution of successive organogenetic and histogenetic events.

• 4 To contribute to better knowledge of late ontogeny in the fetal period, a point neglected so far in all mammal groups.

• 5 To clarify the time course of the reproduction cycle of dolphins by finding out their mating and calving periods.