156 



R UIT 



RUIT 



THE FRUIT 



several valves, already in a high state of tension, the 



toucli which 

 produces the 

 explosion 

 merely in- 

 creasing the 

 stress along tlie lines 

 of delhscence. The 

 opened ^•alves of the Vio- 

 let fruit, constricting, 

 cause tlie forcible expul- 

 sion of the seeds one after 

 another. The hard, bony 

 capsules of tlie Witcli- 



281. B'riiit of AVitoh-hazel discharging liazel (Fig. 281), COIltract- 



ils sreds. - ,1 J 1 



mg, squeeze the smootn, 

 liard seeds with mucli force ; and tlie seeds are shot to a 

 distance of many feet.^ 



Supplementary Reading 



1. Plants tliat Imry their Serils. Liibliock's "Flowers, Fruits, and 

 Leaves," \>\>. S-1-S8. 



'2. The I""i'uits. and Seeds of Plants Parasitic on Trees. Same 

 source, pp. 8-J. SI. 



3. Dispersal of various Fruits and Seeds. Same source. Chap. III. 



4. Dissemination of Plants hy Ocean Currents and by Migrating 

 ISirds. Darwin's --Oiigin of Spiecies," Chap. XT, Dispersal. 



I If a bough wilh the ripe but iDiopened fruits is hung on tlie wall of 

 one's room, the tcrue with which the seeds are ejected and the distance 

 til which they lly are likely to be observed. 



Distances to whicli seeils are eiectcd by several plants are given by 

 Kcrner and Oliver (" Natural History of Plants," 11, 839) as follows : — 



Cardamine iiupatiens .j ft. 



Viola canina .3 ft. 



Geranium palustre 8 ft. 



Lupiims digitattis 23 ft. 



Acantlius mollis 31 ft. 



Hura cri|iitnns 48 ft. 



Bauhinia piiruurea 51 ft. 



