n6 LABORATORY PRACTICE CHAP, xxvm 



CHAPTER XXVIII 



DRY DEHISCENT FRUITS 



DEHISCENT fruits are those which split open to release or 

 even expel the seeds. We may distinguish two classes : 



1. Explosive Fruits, which forcibly expel some or all of 



their seeds, sending them out into the air. 



2. Those which simply open and allow the seeds to fall out, 



leaving them to be dispersed by other means. 



EXPLOSIVE FRUITS 



I. Take the ripening pods of some member of the Pea 

 Family, such as Wistaria, Pea, Bean (with less fleshy pods), 

 etc., and, leaving them in a dry place, examine them from 

 time to time. Sooner or later, they will be found to have 

 split longitudinally, each half or valve of the pod will be 

 found to have twisted itself and to have thrown most of the 

 seeds to some distance. 



Make sketches and notes to illustrate this. 



II. Take also the ripe pods of some species of Violet and 

 watch them in the same way. 



III. Take plants of the garden Balsam (Impatient}, or of 

 Oxalis, and touch the ripe fruits. 



Notice how they suddenly open and eject the seeds. 

 Make notes and sketches. 



