[Action of sulfhydryl compounds on embryonic inducing factors].

Crude extracts from 9 days old chicken embryos containing neuralizing and mesodermalizing inducing factors as well as purified mesodermalizing factor were incubated with thioglycolic acid and with 2-Mercaptoethanol. The fractions were tested by implanting into early gastrulae ofTriturus orAmbystoma. The mesodermalizing factor is inactivated whereas the neuralizing factor does not lose its activity.