COMPOSITION OF CALIFORNIA LEMONS. 
15 
Figure 2 4 shows the specific gravity of the fruit in both varieties 
as harvested monthly. The monthly average shown here must not 
be interpreted too literally, for usually the differences from month to 
month are small. A general trend is shown, however, and there is 
little doubt that the changes from season to season are really signifi- 
cant. For the first four months of the year, the Eurekas change but 
little, while there is a gradual increase in the specific gravity of the 
Lisbons. With the advent of spring, the Eurekas begin to increase 
rapidly, and this increase continues without interruption until mid- 
summer. During the corresponding period, the Lisbons also increase 
rapidly, reaching the maximum in August. From midsummer to 
January there is a marked decline in the specific gravity of both 
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Fig. 2. — Monthly averages of specific gravity. 
varieties. The data leave no doubt that both varieties have the 
lowest specific gravity during the winter months and the highest in 
midsummer. 
Figure 3 shows the variation in the oil content of the fruit har- 
vested each month of the year. Here again indisputable differ- 
ences occur in both varieties, and the general trend of both is very 
much the same. The late winter and spring fruit contains a mini- 
mum amount of oil. The oil content is only slightly increased in 
the su mm er fruit, but with the advent of fall it rises rapidly, until 
December finds the oil content at a maximum in both varieties. 
* In determining the monthly averages, where there are several monthly samples from one tree, the 
average is taken. Where monthly samples are missing, the results are interpolated, the average of the 
preceding and succeeding months being used. 
