THE RELATION BETWEEN INTENSITY OF INDUCTOR AND TYPE OF CELLULAR DIFFERENTIATION OF RANA PIPIENS PRESUMPTIVE EPIDERMIS

Abstract

1. Presumptive epidermis of stage 11 gastrula differentiates into epithelial sheets with ciliated patches. 2. Alteration of the basic salt solution by addition of calcium chloride or magnesium sulfate or sodium bicarbonate results in the differentiation of nerve cells. 3. Calcium chloride, magnesium sulfate, sodium bicarbonate, ammonium sulfate and lithium chloride will induce nerve cells from presumptive epidermis when applied for a few hours beginning with stage 11. 4. Lithium chloride applied to the presumptive epidermis for varying lengths of time induces various cell types. 5. Lithium chloride applied in various concentrations to the presumptive epidermis induces various cell types. 6. A concept of sequential induction is introduced as a formal explanation of the lithium chloride inductions.