5Y STUDIES ON APPLES. 
to 20, inclusive) are much more uniform than in the charts just preced- 
ing, which represent the composition of the summer apples. The 
work on the winter apples began on June 16, 1903, and extended until 
November 5, 1903. These curves illustrate much better the early life 
history of the fruit than those representing the work of the previous 
year. As in that year, the sucrose curve is almost exactly the reverse 
of the starch curve. This is only true, however, after the maximum 
content of starch has been reached, which was between June 30 and 
July 28 with the Ben Davis apples, on July 28 with the Huntsman 
apples, and on June 30 with the Winter Paradise apples. It must be 
understood that no one of these dates is suggested as the exact date of 
the maximum content of starch in the apple. It is only intended to 
represent the maximum cortent of starch on the various dates when 
the apples were examined. On the whole, however, the maximum 
content can not have varied greatly from the date given, and the 
maximum percentage determined must also be approximately correct. 
The observation as to the uniformity of results applies equally to 
all of the determinations made. On the date of the first examination— 
June 16—the content of sucrose based on total solids was 4 per cent. 
The percentage of sucrose increased regularly until the last examina- 
tion, which was made on November 5, when it amounted to 25.4 per 
cent of the total solid content of the.apple, the rate of increase being 
apparently no greater before the maximum content of the starch than 
afterwards. It would appear that during its own growth and accumu- 
lation a portion of the starch is converted into sucrose. Unlike the 
summer apples, the percentage of invert sugar here increased from 
the date of the first examination to approximately the date of the last, 
so that even in percentage composition the amount of invert sugar 
present did not reach its maximum until the maturity of the fruit. 
In all three of the varieties of winter apples studied the percentage 
of malic acid decreased from the first examination to the full maturity 
of the fruit. The percentage of total sugar estimated as invert sugar 
increased steadily from the first examination to full maturity. It is 
a notable fact that after the maximum content of starch is reached 
the percentage of starch and invert sugar taken together remains 
approximately constant. As in the case of the preceding studies, the 
average composition of the three varieties of winter apples has been 
expressed in the form of a composite chart which is given in figure 20. 
In many respects it was considered that a graphic statement showing 
the actual increase in weight of the various constituents of the apple 
determined would have a more definite meaning than the changes in_ 
chemical composition on the percentage basis. Before examination 
each sample was weighed so that the data were secured for this caleu- 
lation. In figures 21 to 28 the changes of the apples just considered, 
both summer and winter varieties, are represented in terms of grams 
per apple, 
