JACQUES LOEB 



89 



Weight of 6 leaves, 8.262 gm. 



The dry weight of the 6 stems without leaves was 0.286 gm. and the fresh 

 weight was 3.935 gm. The dry weight of the 6 half stems containing a leaf was 

 0.688 gm. and the fresh weight 6.203 gm. We have already shown in a previous 

 paper that the mass of an isolated piece of stem increases when a leaf is attached 

 to it.3 



Fig. 4. Showing the enormous difference in mass of shoots regenerated by a 

 half stem with leaf at base and the other half stem without leaf. The stems 

 rested with their cut surface on moist filter paper. 



Hence we can say that only about 5 per cent of the material of the 

 regenerated shoots was contributed by the stem and about 95 per cent 

 of the mass of the regenerated shoots of the stem was formed from 



^ Loeb, Ann. Inst. Pasteur, 1918, xxxii, 1. 



