48. Diversity of devices in the rose family for seed sowing.--All botanists now recognize plants as belonging to separate families, the plants of each family having many points of structure in common. Among these families of higher plants, over two hundred in number, is one known as the rose family. Notwithstanding their close relationship, the modes of seed dispersion are varied. The seeds of plums and cherries and hawthorns are surrounded by a hard pit, or stone, which protects the seeds, while animals eat the fleshy portion of the fruit. When ripe, raspberries leave the dry receptacle and look like miniature thimbles, while the blackberry is fleshy throughout. The dry, seed-like fruits of the strawberry are carried by birds that relish the red, fleshy, juicy apex of the flower stalk. Each little fruit of some kinds of Avens has a hook at the apex, while in Agrimony many hooks grow on the outside of the calyx and aid in carrying the two or three seeds within. Plants of some other families illustrate the great diversity of modes of dispersion as well as the roses. 49. Grouse, fox, and dog carry burs.--To the feathers of a ruffed grouse killed in the molting stage, early in September, were attached fifty or more nutlets of _Echinospermum Virginicum_ Lehm. A student tells of a tame fox kept near his home, on the tail of which were large numbers of sand burs, and a smaller number on his legs and feet. Another student has seen dogs so annoyed by these burs on their feet that they gave up all attempts to walk. Many wild animals unwillingly carry about such fruits, and after a while most of them remove what they can with claws, hoof, or teeth. Many of these plants have no familiar common names, but who has not heard of some of these? enchanter's nightshade, bedstraw, wild liquorice, hound's tongue, beggar-ticks, beggar's lice, stick-tights, pitchforks, tick-trefoil, bush clover, motherwort, sand bur, burdock, cocklebur, sanicle, Avens, Agrimony, carrot, horse nettle, buffalo bur, Russian thistle. Besides these, a very large number of small seeds and fruits are rubbed off and carried away by animals. Some of these stick by means of the pappus, as, for instance, the dandelion, thistle, prickly lettuce; others by means of hairs on the seed, such as those of the willow-herb and milkweeds and willows; or by hairs on the fruit, as virgin's bower, anemone, cotton grass, and cat-tail flag. These last named are apparently designed to be wafted by the wind, but they are ever ready to improve any other opportunity offered, whether it be by water or by clinging to passing animals. [Illustration: FIG. 57.--Whole ripe fruit of the common carrot.] [Illustration: FIG. 58.--Nutlet of stickseed, _Echinospermum_.] [Illustration: FIG. 59.--Fruit of pitchforks, _Bidens_, with two barbed points.] [Illustration: FIG. 60.--A fruit of tick-trefoil, _Desmodium_, and a few of the grappling hooks enlarged.] [Illustration: FIG. 61.--A head of the fruits of burdock.]