Experiments on the Effect of Dyes on Induction and Respiration in the Amphibian Gastrula

Abstract

1. It is shown that pieces of presumptive epidermis (ventral ectoderm of the gastrula), when isolated into weak solutions of several dyes, will undergo neural differentiation. Dyes such as Janus green and neutral red, which are not known to accelerate cell respiration, appear to have this effect, as well as methylene blue, the accelerating action of which on cell respiration is well known. 2. Measurements of the oxygen consumption of isolated pieces of the gastrula by the Cartesian Diver method show that methylene blue, if in weak concentration, has an accelerating action of about 45%. In stronger concentrations it is inhibitory.