JACQUES LOEB 451 



stem, and the same fact is obvious from all the other figures in this 

 paper. It is almost obvious from a glance at the figures that the 

 mass of shoots formed increases with the mass of the stem. If the 

 mass of shoots produced at the apex of large pieces of stem is approxi- 

 mately equal to the mass of shoots which the same stems would have 

 produced had they been cut into as many pieces as the stems con- 

 tained nodes {i.e., into one-node pieces), it will be necessary to show 

 that within the limits of the experimental errors, the mass of dry 

 weight of shoots produced per gram of dry weight of stem is about 

 the same regardless of whether the stems are long or whether they 

 are subdivided into one-node pieces. 



This was tested in various ways. The defoHated stem of a very 

 large plant was cut into 5 pieces, each possessing 4 nodes (Fig. 3), 

 and the defoliated stem of a second plant was cut into 10 small pieces 

 of 1 node each (Fig. 4) . The pieces dipped with the base into water 

 and the large and small pieces were suspended in the same aquarium. 

 The experiment lasted from September 27 to October 22, 1922. The 

 shoots were then cut ofif and both shoots and stems were dried for 

 24 hours in an oven at about 100°C. The result was as follows: 

 The dry weight of the 5 large stems (Fig. 3) was 13.670 gm., and the 

 dry weight of their 16 shoots was 0.495 gm. The shoot production 

 was therefore 36 mg. per gram of stem (all measured in dry weight). 

 The dry weight of the 10 short pieces of stem with 1 node each (Fig. 

 4) was 2.880 gm., and the dry weight of 19 shoots was 0.115 gm., or 

 1 gm. of dry weight of stem produced 40 mg. of dry weight of leaves. 

 These two figures, 40 mg. and 36 mg., agree sufficiently closely to 

 show that under equal conditions the production of shoots of de- 

 foliated pieces of stem occurs in proportion with the mass of the piece 

 of (defoliated) stem; or, in other words, the mass of shoots produced 

 at the apex of the large defoliated stems of Fig. 3 is approximately 

 equal to the mass of shoots the same stems would have produced if 

 all the dormant buds of each stem had been able to grow out. 



The experiment in Figs. 1 and 2 gave a similar result. The experi- 

 ment lasted from October 4 to November 7. 5 large stems with 4 

 nodes each (Fig. 1) having a dry weight of 5.486 gm. produced 10 

 shoots with a dry weight of 0.114 gm.; i.e., 20.8 mg. of shoot per 

 gram of stem. 



