Aug. i6, 1920 Ripening and Storage of Bartlett Pears 481 



fonned may be pentoses, but calculating all reducing substances as 

 dextrose gives a satisfactory comparison. 



Acid. — ^Two 50-gm. portions of the sample were weighed into beakers, 

 about 150 cc. of distilled water were added, and this was immediately 

 boiled to render the cells permeable. After the portions cooled they were 

 made up to 500 cc, 2 cc. of toluol were added to each as a preser\^ative, 

 and they were allowed to stand with frequent shaking for 3 days. One 

 hundred cc. of the supernatant liquid were then drawn off for titration 

 with N/io sodium hydroxid. Duplicate samples made by this method 

 checked very closely. 



Dry weights. — Two 50-gm. samples were weighed directly into evapo- 

 rating dishes. These were then dried down on the steam bath sufficiently 

 to prevent growth of microorganisms ; then when a sufficient number ac- 

 cumulated, they were put in a vacuum oven at 70° F., dried five days, 

 removed and weighed, then returned to the oven for two days. During 

 the last two days the decrease in weight was about 50 mgm. ; but, since 

 all lots were run in exactly the same manner, the results are closely com- 

 parable. All dry weight determinations were made in duplicate, and 

 the figures presented are averages. While considerable variation occurs 

 in successive determinations, duplicates in all cases checked very closely, 



PRESENTATION OF DATA 



The results of all the analyses are summarized in Tables I to IV. Table 

 I includes all the data of fruit from the Sacramento orchard. Table II 

 those from the Willota Orchard at Suisun, Calif., Table III those 

 from Medford, Oreg., and Table IV those from Yakima, Wash. 



