CHANGES ACCOMPANYING BREAKING OF REST PERIOD 



19 



In both cases the CC>2 production fell off very rapidly during the 

 first two days. So far as known, the experimental conditions were 

 exactly the same during these days as during the remaining days, 

 and also similar to the conditions under which the other CO 2 deter- 

 minations were made. The decline in a and b became less marked 

 after the second day. The former fell somewhat more than the latter. 



In III, a is far above b. Curve III6 is the lowest of the curves 

 for CO 2 production of untreated twigs. This determination was 

 made on January 8, in the middle of the dormant season when the 

 normal activity might be expected to be very low. Curve IVa 

 started out much above IVZ>, the one it is compared with, but de- 

 clined fairly uniformly until it actually went below the latter during 

 the fifth day. This curve departed from the behavior shown by 

 la, Ha, and Ilia. All these curves declined much more rapidly 

 during the first day than thereafter, and none of them went below 

 the respective b curves during the time of the experiment. Curve 

 Va behaved somewhat like IVa. It declined even more uniformly, 

 intersecting Vb at the end of the third day. Curve Vb declined less 

 rapidly during the first day than any other curve. After the third 

 day it was higher than any other b curve. This determination was 

 made late in the season. The buds, however, were still dormant, 

 but judging from the behavior of the CO2 production, they had 

 passed their rest period and were held back only by unfavorable 

 weather conditions. 



Some of the points to which attention has been directed are 

 brought out more clearly in numerically expressed ratios between 

 the CO 2 production of etherized and untreated material. These 

 ratios are given in Table 6. The values were obtained in the manner 

 explained before. The last column of the table gives the averages 

 of all the ratios. 



TABLE 6 RATIO OF CO 2 PRODUCED BY ETHERIZED, TO CO 2 PRODUCED 

 BY UNTREATED TWIGS 



* 4th and 5th days. 



The data in Table 6 are represented graphically by the curves 

 in Fig. 6. The ratios in the left hand portion of the figure are laid 

 off on the vertical, the days of experiment on the horizontal. Roman 



