Thus the Squirting Cucumber (Momordica elaterium), a common plant in the south of Europe, and one grown in some places for medicinal purposes, effects the same object by a totally different mechanism. The fruit is a small cucumber, and when ripe becomes so gorged with fluid that it is in a state of great tension. In this condition a very slight touch is sufficient to detach it from the stalk, when the pressure of the walls ejects the contents, throwing the seed some distance. I have seen them even in England sent nearly twenty feet; but in a hotter climate the plant grows more vigorously, and they would doubtless be thrown further. In this case, of course, the contents are ejected at the end by which the cucumber is attached to the stalk. If any one touches one of these ripe fruits, they are often thrown with such force as to strike him in the face. In Cyclanthera, a plant allied to the cucumber, the fruit is unsymmetrical, one side being round and hairy, the other nearly flat and smooth. The true apex of the fruit which bears the remains of the flower, is also somewhat eccentric, and, when the seeds are ripe, if it is touched even lightly, the fruit explodes and the seeds are thrown to some distance. Other cases of projected seeds are afforded by Impatiens, Hura, one of the Euphorbiæ, Collomia, Oxalis, some species allied to acanthus, and by Arceuthobium, a plant allied to the mistletoe, and parasitic on juniper, which ejects its seeds to a distance of several feet, throwing them thus from one tree to another. Even those species which do not eject their seeds often have them so placed with reference to the capsule that they only leave it if swung or jerked by a high wind. In the case of trees, even seeds with no special adaptation for dispersion must in this manner be often carried to no little distance; and to a certain, though less, extent, this must hold good even with herbaceous plants. It throws light on the, at first sight, curious fact that in so many plants with small, heavy seeds, the capsules open not at the bottom, as one might perhaps have been disposed to expect, but at the top. A good illustration is afforded by the well-known case of the common poppy, in which the upper part of the capsule presents a series of little doors, through which, when the plant is swung by the wind, the seeds come out one by one. The little doors are protected from rain by overhanging eaves, and are even said to shut of themselves in wet weather. The genus Campanula is also interesting from this point of view, because some species have the capsules pendent, some upright, and those which are upright open at the top, while those which are pendent do so at the base.