When fresh mouse kidney is boiled (up to 15 min.) the cases of induced brains become rarer (as compared to the original tissue), while the number of induced eyes and noses steadily increases (Chuangs 1 -2 boiling experiment). Because of this inverse behaviour of the brains and the sense organs C h u a n g had supposed the sense organs to be induced by a special inductive substance, which, owing to a progressive inactivation of the brain-inducing substance, grows more and more effective. -When, however, the boiling experiment was repeated and the induced brains were separated into archencephalic and deuterencephalic parts, it became apparent that only the latter are rapidly diminished by the boiling, whereas the archencephalic parts are even slightly increased, similar to the sense organs. Thus the archencephalic inductive effect is generally heightened, not only the number of sense organs. That means that the assumption of a special inductive substance for these organs lades its foundation. -On the other hand, when dryly heated kidney (100° C, 15 min.) had been employed as inductor, the ectoblast exclusively reacted by formation of balancers. Various explanations for that are discussed.

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