20 MISSOURI AGR. EXP. STA. RESEARCH BULLETIN NO. 21 



numerals here as before represent the numbers of the experiments 

 which were performed on the dates given in the upper part of the 

 figure. The heavy horizontal line 1.00 represents the amount of 

 CO 2 produced by the untreated twigs. 



Curve I is only a little above the line for the untreated material 

 Curve II starts out higher than I. It ascends until it reaches a max- 

 imum during the third day after which it begins to decline. Curve 

 III starts out much higher than either I or II. It behaves some- 

 what like II in that it rises until the third day after which it begins 

 to decline. Curve IV starts out over twice as high as III. It declines 

 from the start, at first slowly then more rapidly. It finally cuts 

 line 1.00 during the latter part of the experiment. Curve V starts 

 out rather high but it goes down very rapidly falling below line 1.00 

 even before IV. 



The nearer the close of the dormant season, the shorter was the 

 period during which the etherized twigs produced more CO 2 than 

 the unetherized material. 



In the right hand portion of Figure 6, the numbers of the experi- 

 ment are laid off on the horizontal. Since the experiments were 

 performed approximately one month apart, the points also indicate 

 the various dates during the season. 



Curve A was obtained by plotting the data in the last column 

 of Table 6. This curve again shows that during the early part of 

 the season etherization exerts relatively little influence toward in- 

 creasing the CO 2 production of dormant twigs. This is shown by 

 the proximity of the point I to the line 1.00. A month later the effect 

 of ether was much more apparent. About the first of January the 

 maximum stimulation was obtained. After another month, the 

 stimulating effect of ether became less. It was still less after another 

 month. Curve B in which the ratios obtained on the third day of 

 each experiment are plotted, brings out the same facts. 



In connection with each experiment etherized and untreated 

 twigs were put in beakers of water and placed in the greenhouse 

 where they were allowed to grow. In general, the results obtained 

 were similar to those given by other investigators. During the first 

 part of the season the twigs grew with difficulty. At first etheriza- 

 tion did not cause an earlier growth but later on growth did com- 

 mence rather sooner than in untreated material. When the stim- 

 ulation of CO 2 was most marked, the etherized twigs grew very 

 quickly, several weeks ahead of the untreated. In the latter part 

 of the season the etherized specimens came out only a few days ahead 

 of the untreated, and in the last experiment, the untreated twigs 



