302 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 



fourth columns give the specific gravities of successive new lots of 

 oranges picked at intervals of four days. The specific gravity of these 

 unfrozen oranges does not change appreciably, varying on both sides 

 of .876. The specific gravity of the badly frozen oranges on the tree, 

 however, decreased very rapidly from .850 on January 13 to below 

 .820 on January 30. Stored lemons show the same changes in specific 

 gravity but to a greater degree than was found in stored navel 

 oranges. The sound lemons increased in specific gravity from .890 on 

 January 14 to .968 on February 15, while the badly frozen lemons 

 decreased from .860 on January 14 to below .820 on January 22. 

 We also find that the fruits picked at different times during the 

 experiment (columns 7 and 8), remain practically the same if un- 

 frozen, but decreased very rapidly in specific gravity if badly frozen. 

 We thus see that the specific gravity of the fruit which is frozen 

 decreases rapidly whether it is picked and stored or remains on the 

 tree and that the fruit which is unfrozen increases in specific gravity 

 when picked from the tree and stored. 



Of still more importance than the average specific gravity is that 

 of the specific gravity of the individual fruit. It might be possible for 

 the unfrozen fruit to have a much higher average than the frozen and 

 yet the specific gravity be so variable among the individuals as to 

 make a separation impossible. This is the condition for some time 

 after the freeze. In table 6 is shown the records of individuals. The 

 number of fruit of each density on the date of picking is shown and 

 the number in the same lot of fruit two weeks later. The fruit was 



TABLE 6. Number of Navel Oranges Picked on January 13, 1913 which had a Specific 

 Gravity of Above or Below .87, and their Subsequent Changes. 



Unfrozen Frozen 



Jan. 14, 1913 



Jan. 26, 1913 41 



Feb. 15, 1913 55 



Number of Eureka Lemons Picked on January 13, With a Specific Gravity of Above or 

 Below . 89, and their Subsequent Changes. 



Unfrozen Frozen 



. 89 or below . 89 or below 



above .89 above .89 



Jan. 13, 1913 61 3 12 32 



Jan. 26, 1913 64 2 42 



Feb. 15, 1913 64 1 43 



