IQ2o] 



WAGNESS M TER( III' LAR SP U ES 



(] i 



held in an oven at 30 C. A few were held also at 2 ('. In all 

 cases abundant aeration was provided to prevent the possibility of 

 an accumulation of C0 2 in the air surrounding the fruit. A sum- 

 mary of the data on the internal atmospheres in apples is given in 

 tabic I. 



rABLE I 

 Analyses or gas i\ inter* i u i i \k siwcks of Velloaa Newton \h ■ 



Temperature of Number of p crrrM ,..„ ( . r< , 

 storace°C. determinations ' ' rc entage ^ Ua 



Pen 1 

 CO, h0 



Percentage \ . 

 by difference 



2 



6 



1 1 



20 



30 



3 



27 



31 



29 



6.7 

 8.4 



12. 2 



17.2 

 21.4 



20. 



21.3 



22 .9 

 22 . 7 

 24.6 



79 

 78 



77 

 77 

 75 



. 1 



■7 

 . 1 



3 



■4 



The data presented in table I require but little discussion. It 

 is apparent that the percentage of C0 2 in the gas within the tissues 

 increases markedly at the higher temperatures. At the same time 

 there is a corresponding decrease in the percentage of oxygen 

 present, the average ranging from 14.2 per cent at 2 C. to only 

 3.2 per cent at 30 C. These data, representing averages of a 

 number of determinations, clearly indicate the marked variation 

 that may occur in the composition of gas in the tissues under 

 varying conditions of temperature. 



It is of interest to note that at the lower temperatures the total 

 percentage of oxygen plus that of carbon dioxide is about equal to 

 that of the air. At the higher temperatures, however, and in 

 association with the decreasing amounts of oxygen in the tissues, 

 the sum of these two gases gradually increases. This would 

 indicate that at the higher temperatures one molecule of oxygen 

 liberates more than one molecule of C0 2 . Such data accord with 

 the work of Gerber (5), who found that in fleshy fruits stored at 

 high temperatures acids were mainly respired, and that the ratio 

 of C0 2 to 2 under these conditions was considerably superior to 

 unity. There is also the possibility that at the higher temperature 

 a certain amount of anaerobic respiration is going on, due to the 

 relatively small amount of oxygen present. This would result in 



