2 so STUDIES IN SEEDS AND FRUITS 



ing capsule before dehiscence, the pod turns yellowish green and 

 the white seeds experience the preliminary shrinkage and 

 hardening and take on a greenish hue. Then active drying of 

 the pod and seeds commences ; but before dehiscence begins 

 the shrinking and hardening of the seeds have been almost 

 completed, so that in the opening pod we find normal dark, 

 mottled resting seeds that will perhaps lose another lo per 

 cent, of the original weight in keeping. The respective 

 weights of the seeds in the green pod, in the pod turning 

 yellowish, and in the dried pod on the eve of dehiscing, are 

 8*3, 6*2, and 3-8 grains, which stand to each other as 100, 75, 

 and 46, and thus indicate the three stages of the berry. 



Some of the processes involved in the general shrinking of 

 leo-uminous pods and seeds will be discussed more in detail 

 in the succeeding chapter. Here I will only refer to cases 

 which seem specially suggestive for determining the stages in 

 maturation and in the drying process that are homologous or 

 are truly comparable with those in the capsule and berry. In 

 this connection the pods of Ukx europaus occupied much of 

 my attention. They were the first fruits to which I applied 

 the clue afforded by the Berberis berry. Though much of 

 their behaviour is characteristic of the typical leguminous pod, 

 it is not always that we find the stages so well defined. 



With Ulex europaus practically all the shrinkage, hardening, 

 and coloration of the seeds are carried out in the closed pod ; 

 and when the pod dehisces it exposes to view the normally 

 contracted hard seeds. Three stages in the maturation and 

 drying of the fruit are distinguished by the colour of the seeds. 

 When the green pod has reached its full size they are soft 

 and bright green, a hue that they owe mainly to the dark 

 green embryo which can be seen through the thin coats. Then 

 follows a stage which corresponds seemingly to the first failure 

 of the nutrient supplies from the mother plant. The soft green 

 seeds turn a greenish yellow as the pod begins to dry and darken. 

 But there is no very evident shrinking of the seed, though the 

 cord withers. That is only detected by careful measurement and 



