DISPERSION OF SEEDS. ^ 25 



sooner is the ripenin£T' completed, than tlie capsule 

 becomes almost upright, with the calyx for a support. 

 This position appears to be intended by nature to give 

 more effect to the valvular mechanism for scattering 

 the seeds, as the capsule thus gains a higher eleva- 

 tion (in some cases more than an inch) from which 

 to project them. Some ripe capsules of a fine variety 

 of heart's-ease {Viola tricolor), which I placed in a 

 shallow pasteboard box, in a drawer, were found to 

 have projected their seeds to the distance of two feet. 

 From the elevation of a capsule, therefore, at the top 

 of a tall plant, these seeds might be projected twice 

 or thrice that distance*. 



We may mention, as another very curious illus- 

 tration of the power in plants of discharging their 

 seeds, the remarkable instance of a minute fungus 

 {Sphceroholus stellatus^ Tode). This plant has the 

 property of ejecting its seeds with great force and 

 rapidity, and with a loud cracking noise; and yet it 

 is no bigger than a pin's headt. 



The circumstance alluded to as analogous in in- 

 sects to this admirable contrivance, occurs in the 

 forcible discharge of the eggs of some species to a 

 distance. The ghost moth {Hepialus hmjiuli), 

 for example, ejects its minute black eggs vvith so 

 much rapidity, that De Geer describes them as 

 miming from the oviduct ; and they are sometimes 

 forcibly thrown out like pellets from a pop-gun J. 

 " A friend of mine," says Kirby, " who had observed 

 with attention the proceedings of a common crane- 

 fly {Tipula), assured me, that several females which 

 he caught projected their eggs to the distance of 

 more than ten inches §." Another instance is men- 



* J. R. in Ma^. of Nat. Hist., i. 380. 



■f- For a minute account of this singular plant, see Gieville's 

 Scottish Cryptogamic Flora, No. xxxii. 



X De Geer, Mem. des Insectes, iv. 49 I. 



^ Kirby and Speiice, Intr. lii. G6. 



D 



