JACQUES LOEB 



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petiole of this leaf was removed at the base and also the correspond- 

 ing half of the leaf itself was cut off, though this latter procedure is 

 not essential for the result. The axillary bud of the other leaf was 

 also cut out as in the preceding experiment. Fig. 5 gives the result 

 of such an experiment. The reader will notice that in this case one 

 of the two buds in the first node below the leaf will grow out; namely, 

 that one which lies beneath the removed half of the leaf. This bud 



Fig. 6. Showing that the inhibitory influence of an apical leaf upon shoot 

 formation in the node below the leaf disappears when the size of the leaf is 

 sufficiently diminished. Duration of experiment, Oct. 25 to Nov. 14. 



grows out since it no longer receives any of the sap from the leaf 

 above. I have never seen the other bud in this node grow out. This 

 experiment also succeeds in practically every case. 



We have seen that if we remove one leaf and its axillary bud at the 

 apex of a topped stem, leaving only one leaf at the apex, the buds in 

 the node below are practically always prevented from growing out. 

 When we diminish the mass of the leaf sufficiently (as is done in Fig. 

 6), this inhibitory influence ceases and every plant forms a shoot in 



