PAPERS ON BIOLOGY AND AGRICULTURE 187 



This same experiment was repeated suspending the 



leaves in a saturated atmosphere but not allowing their 

 tips to touch the water. Plate II shows the results after 

 5 weeks. The growth was the same as that just described 

 but the leaves were less turgid. 



Experiment II was designed to show the inhibiting in- 

 fluence of the axillary buds on the growth in the notches 

 of the leaves. Leaf 6, similar to leaf 1, was separated en- 

 tirely from the plant; leaves 7, 8 and 9 had a portion of 

 the stem attached. Both axillary buds were removed 

 from leaf 7, the opposite axillary bud was removed 

 from leaf 8, and no bud was removed from leaf 9. In 

 this experiment B. crenatum gave results different from 

 those obtained by Loeb with B. calycinum. Leaves 6 and 

 9 agreed with leaves 1 and 2 described in experiment I. 

 After 4 weeks, 2 specimens of leaf 7 showed no growth. 

 3 specimens had developed a shoot from the petiole above 

 the cut. In each of the latter, there was "some notch 

 growth although it was much smaller than in leaf 6. 

 Leaf 8 had a shoot from each adjacent axillary bud and 

 also some notch growth. Plate III shows these leaves 

 after 5 weeks. 



Concerning the inhibiting influence of the growth of 

 the axillary buds on the notch growth Loeb states, "It 

 is, therefore, obvious first, that a stem whose buds are 

 removed has still an inhibiting influence upon the for- 

 mation of roots in the notches of a leaf; and second, that 

 if the buds of the stem are not removed, the growth of 

 the bud opposite the leaf enhances this inhibiting effect 

 of the stem upon the leaf considerably. Since the growth 

 of this bud of the stem is as a rule also inhibited when the 

 opposite leaf is not removed, as in figure 3, we under- 

 stand why the non-removal of this leaf favors the growth 

 of the adventitious roots from the notches of the other 

 leaf." In B. crenatum the removal of the buds from the 

 stem did inhibit the notch growth and the inhibiting 

 effect was enhanced by the growth of the bud which was 

 not removed, but the growth of this bud of the stem was 

 not inhibited when the opposite leaf was not removed as 

 was shown by leaf 3. 



