A. 



V? 



a 



h 



S^V-^hT^ ^-f ^^^ specificity of the reaction to the stimulus of induction Bellv 

 HPr? rT n""? f ^^°^ ^^^ FvT^"^^ ^^to the mouth area of a newt embryo^ 

 Here (b, d) it fornis a mouth with horny teeth and a pair of suckers (Hn) 

 Both organs are characteristic of frog larvae, and do not occur in new"s 



After Spemann and Schotte. 



