The hygro- 

 scopic be- 

 haviour of 

 pods. 



STUDIES IN SEEDS AND FRUITS 



to the eye there was a marked increase of weight and a slight 

 softening of the affected materials. 



But I may remark that the more moderate view of the 

 range of hygroscopic variation for seeds is supported by the 

 results of my observations on air-dried fruits. Some of them 

 relating to pods or legumes are tabulated below. 



A. RESULTS OF EXPERIMENTS ON THE HYGROSCOPIC RANGE OF ENTIRE 

 AIR-DRIED LEGUMES OR PODS, INDEHISCENT AND CONTAINING THEIR 

 SEEDS. (The hygroscopic range is the variation in weight stated as a 

 percentage of the total weight.) 



Note. In all the experiments except that on Pea- pods, the pods were kept in one 

 room. The experiments, occupying two months, lasted from June to August. The data 

 for the Pea-pods were obtained by transferring them from a cool and moist room 

 (temperature 50 to 55 F.) to a warm and dry cupboard (temperature 65 to 70 F.) and 

 weighing them after four days. 



B. COMPARISON OF THE HYGROSCOPIC RANGES OF THE AIR-DRIED SEEDS 

 AND FRUIT-CASE OF PISUM SATIVUM (Poo) AND OF IRIS FCETIDISSIMA 

 (CAPSULE) UNDER THE SAME CONDITIONS. 



Iris foetidissima 

 Pisum sativum . 



H. R. of seeds 4*0 per cent. 

 ,, 4*5 .. 



H. R. of fruit-case 3 '6 per cent. 

 ,, 47 ,. 



It will be seen from these tables that the variation in weight 

 in response to the changes in atmospheric humidity was usually 



