Iodine Compounds and Fertilisation

Abstract

ABSTRACT In the earlier papers of this series (Carter, 1930-32) it has been shown that a compound which is related to thyroxine in chemical structure plays an essential part in the fertilisation of the gametes of Echinus esculentus and E. miliaris. Evidence has been brought forward that this substance is present in the ripe egg, being formed during the later stages of its ripening, and that it is concerned in the increase of chemical activity which occurs in the egg after fertilisation. It is probably identical with or closely related to Lillie’s fertilizin. It is also present in the egg secretions and in the ripe sperm. Further, the similarity between the effects produced by the secretions and by thyroxine on sperm which was not perfectly ripe (in the sense previously defined, 1931 a, p. 180), and the fact that the behaviour of such sperm in the presence of thyroxine became identical with that of ripe sperm led to the conclusion that this substance is formed within the sperm during the later stages of its ripening, as it is formed in the ripening of the egg.