GERANIUM TlilBE 161 



"Each seed, of which there are five to each flower," says the writer, "is 

 inclosed in a carpel, attached by its upper extremity to a t;'il or awn, which 

 possesses the most wonderful hygrometric sensibility, as, indeed, does every 

 other part of the plant. These five awns lie in grooves in the receptacle of 

 the flowers, and this receptacle is central to, and is the axis of, all parts of 

 the flower and fruit. When the whole system has arrived at a certain point 

 of aridity, the awns, which are provided with an exquisite power of torsion, 

 twist themselves out from their grooves, and at the same moment a number 

 of downy filaments, hidden in the back or inward face of the aAvns, bristle 

 forth ; they all together become now detached, and fall to the ground. 



"But here they still continue to twist, and from the position in which 

 they always lie, keep tumbling over and over, and thus receding from the 

 parent plant, until at length they become perfect balloons, ready to be wafted 

 away by every zephyr. But motive power has not ceased to this apparatus 

 to the seeds when this has twisted itself into this balloon shape ; the slightest 

 hygrometric change produces motion either backwards or forwards in the 

 awn, and the constant tendency of this motion is to screw the seed into the 

 ground. Such is the shape and great sensibility of the awns, that they may 

 be readily applied to form most delicate differential hygrometers, for which 

 purpose I have used them." 



Mr. Mallet, in recording his observations, has allowed his imagination to 

 run somewhat in advance of facts ; but, with the exception of the " balloon " 

 simile, his remarks are very just. 



Order XXI. BALSAMINEvE— BALSAM TRIBE. 



Flowers irregular ; sepals 5, or appearing to be 4, by two of the upper 

 or inner ones uniting into one, the lowest spurred and hooded ; petals 5, but 

 appearing to be only 2, by the union in pairs of the four side ones, and the 

 fifth being wanting ; stamens 5 ; filaments more or less united at the 

 extremity ; anthers 2-celled ; ovary of 5 cells, alternating with the stamens ; 

 stigmas 5, almost sessile, either distinct or united ; fruit a capsule, with 

 5 elastic valves and 5 cells, or succulent, and not bursting ; seeds 1, or many, 

 suspended. The plants composing this Order are juicy and herbaceous, with 

 opposite and alternate leaves, destitute of stipules. They are natives of 

 damp marshy places among bushes, and are not remarkable for any medicinal 

 properties. They have all a curious method of projecting their seeds to a 

 distance. 



Balsam {Impdtiens). — Flowers of apparently 4 sepals, and 2 petals; 

 capsule of 5 valves. Name signifying impatient, given from the sudden 

 opening of the valves of the capsule Avhen touched. 



Balsam {Impdtiens). 

 Yellow Balsam, or Touch-me-not (/. noli-me-tdngere). — Joints of the 

 stem swollen ; leaves egg-shaped, serrated and stalked; stalks 3 or 4-flowered; 

 spur of the calyx loosely recurved, and entire at the point. Plant annual. 

 This is very rare as a wild plant, growing in moist woods in North Wales, 

 Westmoreland, and Ireland, and flowering in July. It has been found in 

 the neighbourhood of Keswick, in Cumberland ; by the side of Coniston 



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