



COMPOSITION OF GASES IN INTERCELLULAR SPACES 



OF APPLES AND POTATOES 



i. 



It consists of a leveling bottle or burette (^4), connected through 

 heavy walled rubber tubing to a side neck at the base of a thick- 

 walled glass cylinder (B). This cylinder is flared at the top, and 







CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 271 



J. R. Mag ness 



(with one figure) 



Introduction 



During a study of the ripening processes in fruits, and the 

 chemical and physiological changes associated with them, the 

 question has arisen as to what may be the composition of the gas 

 in the intercellular spaces. The gas within the tissues constitutes 

 in part the medium in which the processes associated with the life 

 of an organism take place. It is only reasonable to suppose that 

 the composition of this medium may exert some influence upon 

 the rate or nature of the changes taking place. The difficulty of 

 extracting the gases from the interior of the tissues is probably 

 responsible for the fact that plant physiologists have almost 

 entirely neglected studies along this line. Gerber (5) reports 

 work of Fremy published in 1840 and i860, in which the gas con- 

 tained in apples was analyzed at intervals during their develop- 

 ment and ripening. He found oxygen more abundant in the 

 green fruit, the amount decreasing as the fruit matured on the 

 tree. We have, however, no critical studies upon the internal 

 gases of plant tissues. 



An apparatus has been devised for obtaining a sample of the 

 gas from within the tissues, without contamination with air. It 

 is the purpose of this preliminary report to describe the apparatus 

 and methods of sampling, together with the data secured, in 

 order that they may be available to workers along related lines. 



Apparatus 



The apparatus used in extracting the gas is shown in fig. 



' 



Botanical Gazette, vol. 70] 



[308 



