280 



STUDIES IN SEEDS AND FRUITS 



Those of Arenaria peploides behave like the fruits of Stellaria 

 Holostea above described. Although detached capsules of 

 Datura Stramonium lost 18 per cent, of their weight in my 

 experiments before they dehisced, it is highly probable that, 

 like those of Iris, when kept in wet moss they would have 

 opened without any drying at all. In the same way the moist 

 mature fruits of the Primrose (Primula verts), after lying one 

 night on my table, were found to be dehiscing and to have lost 

 about 20 per cent, of their weight. But observation of the 

 capsules on the living plant led me to consider that the first 

 stage in dehiscence begins still earlier in the drying process. It is 

 singular that the normal opening of the Primrose capsule at the 

 top may be prevented by making a hole in its base. Appended 

 are the results of my observations on the dehiscence of detached 

 mature capsules of Primula verts and Datura Stramonium, when 

 allowed to dry on my table. Though obviously such experi- 

 ments are not carried out under nature's conditions, their results 

 will serve to illustrate the early opening of capsular fruits. 



THE DRYING IN AIR AND DEHISCENCE OF DETACHED RIPE 

 CAPSULES OF DATURA STRAMONIUM AND PRIMULA VERIS. 



In a species of Aquilegia growing in my garden the opening 

 of the follicles took place shortly after the period of maximum 

 growth. The green follicles are completely closed ; but as 

 they ripen they acquire a purplish tinge and gape open at the 

 base before normal dehiscence occurs. In such mature fruits 

 the cohesion at the ventral suture becomes very slight, and a 

 slight increase of the tension due to some external cause would 



