ISOGAMY, term applied in biology to conditions in which the sexual cells (gametes, q.v.) are alike, in contradistinction to betero gamy or anisogamy, where the gametes are differentiated into male elements (spermatozoa or spermatozoids) and female ele ments (ova). Isogamy occurs in some of the lower Algae and
certain Protozoa, but it would seem that in most cases, if not in all, the gametes do not behave alike, so that they are function ally anisogamous. (See FERTILIZERS, PROTOZOA, ALGAE, REPRO DUCTION.)