out through the open side. In the Cranesbills the jerk is so violent that seeds may be flung to a distance of twenty feet. One of the most efficient of all devices of this kind is found in the Sand-box Tree (_Hura crepitans_), a native of South America. By sudden rupture and twisting of the carpels of the woody sub-globular fruit, the large seeds of this plant are thrown to a distance of thirty yards, the explosion being accompanied by a report like that of a pistol-shot. In the common Dog Violet (_Viola Riviniana_) (Fig. 10) the fruit is a three-valved capsule, which on ripening divides; each valve assumes a horizontal position and its edges contract till it is shaped like an open boat, the seeds lying in a row down the middle. The sides as they dry close in tighter and tighter on the seeds, which are in turn pinched out, and fly off with a little snap to a distance of many feet. It is an interesting experience to watch these tricks of Nature--much more interesting than merely to read about them. If plants of Vetch, Gorse, Dog Violet, Storksbill, Wood Sorrel, Touch-me-not (to name a few), bearing unripe fruit, be brought home and placed in water in a sitting-room, the click of the bursting fruits will be distinctly audible, and by spreading a white sheet the efficiency of the devices may be tested. [Illustration: FIG. 10.--FRUIT OF VIOLA. 3/4. _a_, Mature capsule; _b_, capsule open ready to discharge seeds; _c_, capsule after seeds are discharged.] A very interesting case, in which the seed is actually buried in the soil by movements of its appendages (portions of the parent plant which remain attached to it), may be watched in the case of the Storksbills (_Erodium_), Several species of which are British plants of frequent occurrence. Here the young fruit much resembles that of its allies the Cranesbills. The long rod-like axis at the lower end of which the seed is enclosed contracts unequally in drying, so that the upper half assumes a position at right angles to that of the [Illustration: FIG. 11.--FRUIT OF STORKSBILL (ERODIUM). 2/3. _a_, Mature, twisting beginning; _b_, separate fruit, fully twisted.]