24 STUDIES ON APPLES. 



DISCUSSION OF ANALYTICAL DATA. 



Ity referring to the graphic chart of Rhode Island Greening apples 

 (fig. 1) it will be noted that the examination made on August 25 gave 

 a sucrose content of 13 per cent on the basis of total solids. The con- 

 tent of sucrose increased steadily until about November 7, when the 

 maximum was reached. During this time the content of starch had 

 decreased, and the curve representing the decrease of starch is almost 

 the reverse of the curve representing the increase of sucrose. The 

 sucrose reached the maximum on the date mentioned, November 7, 

 after which it rapidly decreased, and the date of the disappearance of 

 the starch was almost, if not quite, coincident with that of the maxi- 

 mum content of sucrose. 



The entire crop of apples was picked between October 6 and Novem- 

 ber 7, and unfortunately during that period, owing to the congested 

 condition of the railroads, it was impossible to obtain samples of fruit, 

 and the changes of composition taking place just at the time of ripen- 

 ing were not studied in as great detail as had been planned. It is 

 probable that after picking the changes of composition may have pro- 

 gressed more rapidly than would have been ( In- case if they could have 

 been left on the tree. 



The sum of the starch and sucrose (March calculated as sucrose) is 

 shown to decrease up to the point where the starch entirely disap- 

 peared. After this time the sucrose content decreases much more 

 rapidly. The content of invert sugar increases from the earliest 

 examination throughout the experiment. The curve representing the 

 content of invert sugar is approximately the reverse of the curve 

 representing h'rst the decrease of starch and sucrose, and later the 

 decrease of sucrose. 



It will also be noted -on the chart (fig. 1) that the total content of 

 sugar (calculated as invert sugar) increased from the h'rst examination 

 to the date of the disappearance of the starch. After this date the 

 curve representing the total sugar as invert merges with the curve 

 representing the total carbohydrates as invert sugar. This latter 

 curve does not include the cellulose. In the Rhode Island Greening 

 apples the total carbohydrate content decreased to some extent after 

 the disappearance of the starch. In the cases of the other varieties of 

 apples previously mentioned, and some varieties to be described later, 

 the percentage of total carbohydrates did riot" materially change 

 during the later stages of the growth and development of the fruit. 



At the same time a slight increase of carbohydrates expressed in 

 terms of total solids seemed to occur during the growth of the apple 

 before its separation from the tree, and a decrease occurred after 

 picking, especially during long storage. Up to the point of the 

 maximum starch content the percentage of total carbohydrates 

 increases' rapidly. This point is discussed in greater detail subse- 



