14 BULLETIN 993, U. S. DEPARTMENT OE AGRICULTURE. 
from 0.898 to 0.915, with the average shown in Table 7. Here it is 
perfectly apparent that the difference is one between the varieties, 
for the maximum specific gravity of Lisbon strains is lower than the 
minimum specific gravity of the Eureka strains. This difference 
corroborates that already found between the regular samples of 
each variety. 
When the averages for oil are considered, the results are less satis- 
factory. The averages for all the Eureka strains vary between 7.6 
and 11.2 pounds per ton; on the other hand, the Lisbon averages 
vary from 8.6 to 12.9 pounds per ton. The averages in Table 7, 
with the probable error of the means, show that the. odds are 7 to 1 
that the difference is significant in the case of these samples. Whether 
or not this significance would be maintained throughout the entire 
plantings of the State would depend largely upon the preponderance 
of the strains having high oil content. At present no data estab- 
lishing such a preponderance are available. 
Likewise, the acidity of the juice of the Corona samples shows 
some difference between the varieties, but there is a similar differ- 
ence between the strains within the varieties, so that this is not 
significant when the varieties are considered as a whole. 
The same conditions apply to the averages on percentage of rind 
shown in Table 7. Apparently nothing significant in the averages of 
the insoluble solids is shown, although a significant difference is 
apparent in some of the strains within the variety. 3 
The averages for sugar show a rather marked difference, which 
is more significant between the varieties than between the strains 
within the variety. Only a single Lisbon strain has an average sugar 
content greater than 2 per cent, while not one Eureka strain has an 
average below that figure. Therefore, the odds of over 200 to 1 
that the difference is significant probably apply to the varieties as a 
whole. 
SEASONAL DIFFERENCES. 
The marked differences found in the samples of lemons harvested 
at different times of the year are interesting. As previously stated, 
lemons may be harvested during every month of the year, the selec- 
tion being made according to size and not according to color. As 
the samples were harvested in the same manner as the commercial 
fruit, the changes which are discussed in the following pages are due 
not to the different stages of maturity but to the composition of 
fruit maturing at different times of the year. All of the samples 
analyzed were commercially mature. 
3 This difference will be discussed in a forthcoming publication. 
