290 STUDIES IN SEEDS AND FRUITS 



by means of the balance. As shown in the results below 

 tabulated, the stage in the drying process at which dehiscence 

 occurred corresponds closely with that obtained for typical 

 leguminous pods of the genera Vicia^ Ulex, and Casalpinia^ as 

 before given. 



Drying and Dehiscence of a Fruit of Hura crepitans. 

 (See above for explanation.) 



But the resemblance between a coccus of Hura crepitans 

 and a leguminous pod is not merely concerned with the stage 

 at which dehiscence occurs, but also extends to the mode 

 of the dehiscence. Each woody coccus splits along the back 

 more or less completely into two valves, whilst at the same 

 time it detaches itself with violence from the central axis and 

 carries the seed away for many yards. After the rupture each 

 valve displays a very slight spiral twist, thus indicating that 

 the mechanism of dehiscence is similar to that of the legume, 

 which after its sudden opening shows two spirally twisted 

 valves. 



SUMMARY 



(i) One is apt to associate the process of dehiscence with dry 

 fruits, and both the capsule and the legume are usually classed among 

 dry fruits ; but the author's observations indicate that this association 

 applies more especially to fruits like legumes that usually only dehisce 

 after they have almost completed the drying process, and that as a rule 

 it does not concern capsules. Whilst the legume dehisces after drying, 

 the capsule dehisces before drying begins. 



(2) The author's results bring him into line with the view 

 expressed by Professor Pfeffer that whilst the phenomena of dehiscence 



