The differentiation-pattern in dependence of the proportion between inducing and induced cells studied on gastrula-ectoderm of Ambystoma mexicanum.

The dependence of the differentiation-pattern of competent amphibian ectoderm on the proportion of inducing and induced material was studied. To do so different masses of LiCl-treated tissue were combined with a constant mass of untreated material. LiCl-treated isolates corresponding in size with the treated portions in the combinations served as controls. The experiments seem to show at least three factors responsible for the differentiation-pattern of the combinations: the number of inducing cells, the number of cells to be induced, and the competence of the ectoderm, which depends on the stage of development.