Page:Popular Science Monthly Volume 19.djvu/374

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the ovary which constitutes the edible part of the fruit, and in which the pips are imbedded. At first sight, the fruit of the mulberry—which, however, belongs to a different family—closely resembles that of the blackberry. In the mulberry, however, it is the sepals which becomes fleshy and sweet.

The next point is that seeds should be in a spot suitable for their growth. In most cases the seed lies on the ground, into which it then pushes its little rootlet. In plants, however, which live on trees, the case is not so simple, and we meet some curious contrivances. Thus, the mistletoe, as we all know, is parasitic on trees. The fruits are eaten by birds, and the droppings often, therefore, fall on the boughs; but if the seed were like that of most other plants it would soon fall to the ground and consequently perish. Almost alone among English plants it is extremely sticky and thus adheres to the bark.

PSM V19 D374 Myzodendron.jpg
Fig. 16.—Myzodendron. (After Hooker.)

I have already alluded to an allied genus, Arceuthobium, parasitic on junipers, which throws its seeds to a distance of several feet. These also are very viscid, or, to speak more correctly, are imbedded in a very viscid mucilage, so that if they come in contact with the bark of a neighboring tree they stick to it.