88 



REGENERATION OF BRYOPHYLLUM CALYCINUM 



sorption of water by the leaf. The duration of these experiments had 

 to be short on account of the more rapid wilting of the leaves connected 

 with the stems. 



In this case the disturbing factor of wilting is greater than when the 

 apices of the leaves dip into water and hence the results with leaves 

 suspended entirely in air show a smaller approximation to propor- 

 tionality between mass of leaves and mass of shoots produced by the 

 stem than that demonstrated in Table I, although the proportionality 

 is not entirely obliterated. 



TABLE II. 



Stems and Leaves Suspended in Moist Air. 



No. of 

 experi- 

 ment. 



Dura- 

 tion of 

 experi- 

 ment. 



days 



17 



19 



C) whole leaves 



6 " sister leaves 



6 whole leaves 



6 sister " reduced in size 



Regenerated 

 shoots per 

 gm. of leaf. 



nig. 

 119 

 151 



168 

 237 



III. 



The mass of shoot produced in an isolated piece of stem entirely 

 deprived of leaf is small compared with that produced when a leaf is 

 attached to the base of the stem. This was demonstrated in the 

 following experiment. 



Six stems, each containing three nodes and one leaf at the base, 

 were split longitudinally in the way described above. One half stem 

 contained one leaf at the base, the other had no leaf. To insure an 

 equal water supply to the stems they were put with their cut sides on 

 moist filter paper (Fig. 4), the leaf at the base of the one set of stems 

 being in moist air. The duration of the experiment was 24 days. 



Fresh weight of shoots produced in 6 half stems ivitliout leaves, 0.120 gm. (dry 

 weight, 0.0105 gm.). 



Fresh weight of shoots produced in 6 half stems icith leaves, 2.088 gm. (dry 

 weight, 0.2015 gm.). 



