98 



REGENERATION 



apical node and in the second node below the apex will form no 

 shoots in the first node below the apex (Fig. 75). The inhibitory 

 effect of the two apical leaves is too great. When, however, 

 there is only one leaf in the apical node and one leaf in the second 

 node below, but on the opposite side of the stem, and if in addition 

 the bud opposite the apical leaf is cut out, the shoots in the 

 first node below the apical leaf may grow out (Fig. 76). The 

 inhibitory effect of one apical leaf on the buds in the first node 



Fig. 75. — One pair of leaves at apex and one pair at second node below, in a 

 young stem. The influence of the basal leaves does not suffice to overcome 

 the inhibitory effect of the two apical leaves on the shoot formation in the node 

 in the middle of the stem. Nov. 20 to Dec. 17. 



below the apical leaf is only half of that of two leaves (of the 

 same size) and this inhibition can be overcome by a basal leaf. 



When this experiment is repeated with stems in which the buds 

 in the first node below the leaf are cut out, the axillary shoot of the 

 leaf at the apex will grow out though usually with some delay 

 (Fig. 77). 



In all these experiments the inhibitory effect of the apical leaf 

 is stronger for those anlagen of shoots which lie in the middle of 

 the path of the descending sap from the apical leaf than for those 



