227 
conspicnons 7 as was mentioned before, in the Wood Sorrel (Oxalis Corni- 
culata), and the Wild Cucumber (Mqmordica); but more particularly in 
our common garden Balsam , whose pericarp consists of five valves so united 
as to appear one homogeneous body, but when touched (hence the balsam 
is called Noli me tangere) some, or all of these divisions, suddenly fold 
back into a spiral form, and ejaculate the seeds to a considerable distance. 
The same may be said of the Spurge (Euphorbia), Dittany (Dictamnus), 
and Phillanthus. Several seed-vessels burst with an explosive force, 
and throw the seeds to a distance, says Lord Karnes, in the Gentleman 
Farmer, and this is the case with our Whin (Ulex) Furze; for did the seeds 
fall perpendicularly down, they would be suffocated in the heart of an 
impenetrable bush. On a clear summers day, says Dr. Smith, they produce 
an agreeable crackling noise. But the most remarkable instance is the 
Sand-box tree (Hura Crepitans), whose ripened pericarps explode in a 
bright sun-shine every five or ten minutes with the noise of a pistol. 
The seeds of the Harfs-tongue (Asplenium) are shot out by a very 
artful contrivance. The capsule is an hollow ball, nearly surrounded by an 
elastic ring, which, like a bow, is stretched to its highest pitch of elasticity, t, 
when it shoots back, separating the bail into two hemispheres, thus ejacu¬ 
lating the seeds. 
If a moderate quantity of the minute capsules of Fern (Filix), says 
Ray, be shaken upon a sheet of white paper and gathered into a heap, by 
these starting asunder and striking each other, the whole heap will appear 
to be in motion in several parts, as if filled with small live insects; and if 
the place be still, by approaching the ear to the heap, one may hear the 
sound of the little vesicles crackling as they burst, and observe the seeds 
flying off, scattered to a considerable distance from the heap. 
The pericarp of the Geranium , and the arista, or beard of the Wild Oat 
(Avena Fatua), are twisted, doubtless, for a similar purpose, and, being 
extremely sensible to the changes of the atmosphere, readily dislodge their 
seeds on wet days, when the earth is best fitted to receive them. The 
former of these has a kind of feathery leg, which occasions it be rolled along 
by the least breath of air; or it may elongate and contract, like the walking 
oat , and thus creep along the ground. * 
The Bose of Jericho (Anastatica), is equally curious, and well known. 
* The awns of the Geranium have been used as hygrometers by striking the base of the seed 
into a cork for a pedestal, and marking divisions on a paper circle beneath it. The awn of the 
