18 POMOLOGY 



time of picking and the time of full ripening of the fruit when 

 held at 70° F. There was much less acid in fruit ripened at 

 40° than in that ripened at 70°, and still less in fruit that had 

 been held at 30°. The acid content of fruit that was allowed 

 to become well matured on the tree remained nearly con- 

 stant during storage." Since there was always a greater 

 amount of acid in fruit which was removed and ripened at 

 70° F. than when the fruit was picked from the tree, it be- 

 comes " of interest especially in connection with the question 

 of whether fruit acids are synthesized in the fruit itself or 

 whether they are carried to the fruit from the leaves. The 

 fact that there is an increase in the acid between the time the 

 fruit is removed from the tree and the time of its becoming 

 ripe is evidence that there is an actual synthesis of acid 

 in the fruit itself. 



"There was a progressive reduction in the alcohol-insol- 

 uble, acid-hydrolyzable reducing material as the season 

 advanced, not only in the fruit fresh from the tree, but also 

 in the same fruit after ripening. There is a marked reduction 

 in these substances between the time when the fruit is first 

 picked and the time when the same fruit becomes ripe. 



"The percentage of total solids is lowest at about the 

 opening of the commercial season. This tends to increase 

 with the accumulation of sugar in the late-picked lots." 



