82 MASS. EXPERIMENT STATION BULLETIN 198. 



yeast in alcoholic fermentation. Similar results are found with fruits. 

 Carbon dioxide has been found to be exhaled by fruit in nitrogen gas ^ at 

 about the same rate as by fruit in air. The destruction of sugar under 

 such conditions is theoretically twelve times as great as when oxygen is 

 available.^ 



In our work with cranberries the rate of destruction of sugar in tight 

 packages was shown to be much greater than in well- ventilated ones. At 

 the same time, it was noted that many berries were very resistant to the 

 conditions, and showed little or no signs of asphyxiation. It is possible 

 that such berries have a lower rate of chemical activity, because, as Gore ^ 

 has shown, the varieties of fruit which may be kept a long time, like oranges 

 and lemons, have a much lower rate of respiration than fruits like grapes 

 and strawberries, which spoil quickly. 



A third study of the rate of respiration was made in January and Febru- 

 ary, 1920, with the object of learning whether the different varieties 

 varied in their activity at a given temperature. It was necessary to have 

 as constant a temperature as could be maintained with the means at our 

 disposal. Through the co-operation of the Pomology Department we 

 were enabled to carry on the work in one of the cold-storage rooms in 

 which the temperature changes were comparatively small and slow, and 

 the different varieties were studied under closely comparable conditions. 



The cranberries were received from the Experiment Station bog in 

 November, 1919, and had been held in a room yviih apples at a tempera- 

 ture of 32° to 33° F., until the respiration experiment was reached in Jan- 

 uary. They were then transferred to the room in which the respiration 

 apparatus was set up, so that they would be at the temperature of the trial 

 at all times. Four varieties of cranberries were used. The Howes variety 

 was studied, with especial attention to possible changes in the rate of 

 respiration as the storage period advanced, and the other varieties were 

 compared with the Howes and with each other, as there was opportunity. 

 A fresh lot of berries was taken from the crate and carefully hand-sorted 

 for each day's trial in order to exclude any unsound fruit. The experi- 

 ment was conducted as in all the previous cases. 



1 Hill, Cornell Univ. Agr. Expt. Sta. Bui. No. 330. 



2 Palladin, Plant Physiology, tr. by Livingston, Blakiston, 1918, p. 180. 

 8 Gore, U. S. Dept. of Agr., Bur. of Chem. Bui. No. 142. 



