=Wind Travelers.=--Wind-transported seeds are of two general kinds: those that are _provided with wings_, as the flat seeds of catalpa (Fig. 251) and cone-bearing trees and the samaras of ash, elm, tulip-tree, ailanthus, and maple; and those which have _feathery buoys_ or _parachutes_ to enable them to float in the air. Of the latter kind are the fruits of many composites, in which the pappus is copious and soft. Dandelion and thistle are examples. The silk of the milkweed and probably the hairs on the cotton seed have a similar office, and also the wool of the cat-tail. Recall the cottony seeds of the willow and poplar. [Illustration: FIG. 251.--WINGED SEEDS OF CATALPA.] =Dispersal by Birds.=--_Seeds of berries and of other small fleshy fruits are carried far and wide by birds._ The pulp is digested, but the seeds are not injured. Note how the cherries, raspberries, blackberries, June-berries, and others spring up in the fence rows, where the birds rest. Some berries and drupes persist far into winter, when they supply food to cedar birds, robins, and the winter birds. Red cedar is distributed by birds. Many of these pulpy fruits are agreeable as human food, and some of them have been greatly enlarged or “improved” by the arts of the cultivator. The seeds are usually indigestible. =Burs.=--Many seeds and fruits bear spines, hooks, and hairs, which _adhere to the coats of animals and to clothing_. The burdock has an involucre with hooked scales, containing the fruits inside. The clotbur is also an involucre. Both are compositous plants, allied to thistles, but the whole head, rather than the separate fruits, is transported. In some compositous fruits the pappus takes the form of hooks and spines, as in the “Spanish bayonets” and “pitchforks.” Fruits of various kinds are known as “stick tights,” as of the agrimony and hound’s-tongue. Those who walk in the woods in late summer and fall are aware that plants have means of disseminating themselves (Fig. 252). If it is impossible to identify the burs which one finds on clothing, the seeds may be planted and specimens of the plant may then be grown. [Illustration: FIG. 252.--STEALING A RIDE.]