ISOLATED LEAVES OF BRYOPHYLLUM 



15 



accuracy of the experiments equal quantities of dry weight of 

 roots and shoots. The tips of the two sets of leaves dipped into 

 water, and roots and shoots developed only in the submerged 

 notches (Fig. 16). 



Experiment 4, — ^Leaves were suspended sidewise, their lower 

 edges dipping in water (Fig. 17). In both sets of leaves the upper 

 edge was cut off; in one set the lower edge with the exception of 

 one or two notches was cut off (Set I), while in the other set (Set 

 II) all the notches of the lower edge were left intact. This was 



Fig. 17. — Sister leaves suspended sidewise. The upper edge is cut off in 

 both leaves. In leaf to left, all notches except one removed; in leaf to right, 

 all notches on the lower side preserved. Duration of experiment 33 days. 

 After nature. 



done to make the number of shoots produced by both sets 

 unequal and to show that the general law enunciated remains 

 true, even if the number of shoots produced in the two sets of 

 leaves differs considerably. Thus, the leaves of Set I produced 6 

 and the leaves of Set II produced 16 shoots, yet the mass of the 

 two sets of shoots was approximately the same, although it seems 

 that when more shoots develop in one leaf the available material 



