Gamete synonyms

Ectocarpus siliculosus, female gamete surrounded by male gametes.

Usually, however, only one of the fusing cells is a zoogamete, the other gamete being a much larger resting cell.

This view is still maintained by those who differentiate two acts of fertilization within the embryo-sac, and regard that of the egg by the first male-cell, as the true or generative fertilization, and that of the polar nuclei by the second male gamete as a vegetative fertilization which gives a stimulus to development in correlation with the other.

a, antherozoids, b, a female gamete.

In Sirogonium there is cell-division in the parent-cell prior to conjugation; and as two segments are cut off in the case of the active gamete, and only one in the case of the passive gamete, there is a corresponding difference of size, marking another step in the sexual differentiation.