92 



REGENERATION OF BRYOPHYLLUM CALYCINUM 



TABLE III. 



VI. 



If it is true that the leaf furnishes the material to the stem from 

 which the regenerating shoot grows, it should be possible to show that 

 the basal leaf in connection with a regenerating stem has (after some 

 time) less weight than the sister leaf which is separated entirely from 

 the stem. This can indeed be demonstrated. A piece of stem is cut 

 from a plant and all the leaves are removed except the two leaves at 

 the basal node of the stem. One basal leaf is entirely separated from 

 the stem to serve as a control; the other leaf remains in connection 

 with the stem. 



Six stems, about 6 cm. long, with several nodes and with a basal pair 

 of leaves of, approximately or practically the same size were selected 

 for the experiment. Such sister leaves of the same size have also 

 practically the same mass as shown in previous experiments. Both 

 the isolated leaves and the stems with one leaf attached were sus- 

 pended in moist air, in the same aquarium under identical conditions 

 of light, temperature, and moisture. After 16 days the fresh and dry 

 weights of the two sets of leaves, namely of the detached leaves and 

 of their sister leaves connected with the stem, were ascertained. 

 It was found that the leaves connected with the stems weighed con- 

 siderably less than the detached leaves, and the difference was far in 

 excess of the natural variation in the weight of fresh sister leaves of 

 equal size. 



