Morphologische Aspekte der Dotterresorption in der späteren Embryonalperiode von Octopoden unter besonderer Berücksichtigung von zwei Eledone-Arten

Based on serial sections and information in the literature. the relations of the external and the internal yolk sac as well of the yolk stalk are described during the later embryonic development and around the hatching stage of some incirrate Octopods. The internal yolk sac diminishes till stage XVI of NAEF; as a consequence of the storing of yolk from the external yolk sac, it again incrPases afterwards. However, in Octopus vulgaris and especially in Argonauta argo, the inner sac is always relatively voluminous. After stage XVI, Eledone moschata does not again store yolk in the internal yolk sac. Eledone moschata hatches either without yolk reserves or with an ingluvies filled with yolk from the external yolk sac