Abstract
Some factors controlling the dif-ferentiation of sporangia and gemmae in an isolate of Achlya sp. were investigated by replacement culture technique. Factors in the replace-ment medium which affect differentiation were as follows: (1) Ca was required for the differentiation of both sporangia and gemmae: (2) Ca could not be replaced by Mg, K, or Na; (3) gemmae were induced when the replacement medium contained salt at 40-80 m[image]; (4) The salt in-duction of gemmae was nonspecific, with Na, K, Mg, and Ca chlorides equally effective.