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There are two ways in which animals may be employed to disperse seeds–voluntarily and involuntarily. They may be compelled to carry them against their wills: or they may be bribed and cajoled and flattered into doing the plant’s work for it in return for some substantial advantage or benefit the plant confers upon them. The first plan is the one adopted by burrs and cleavers. These adhesive fruits are like the man who buttonholes you and won’t be shaken off: they are provided with little curved hooks or bent and barbed hairs which catch upon the wool of sheep, the coat of cattle, or the nether integuments of wayfaring humanity, and can’t be got rid of without some little difficulty. Most of them, you will find on examination, belonged to confirmed hedgerow or woodside plants: they grow among bushes or low scrub, and thickets of gorse or bramble. Now, to such plants as these, it is obviously useful to have adhesive fruits and seeds: for when sheep or other animals get them caught in their coats, they carry them away to other bushy spots, and there, to get rid of the annoyance caused by the foreign body, scratch them off at once against some holly-bush or blackthorn. You may often find seeds of this type sticking on thorns as the nucleus of a little matted mass of wool, so left by the sheep in the very spots best adapted for the free growth of their vigorous seedlings.

Even among plants which trust to the involuntary services of animals in dispersing their seeds, a great many varieties of detail may be observed on close inspection. For example, in hound’s-tongue and goose-grass, two of the best-known instances among our common English weeds, each little nut is covered with many small hooks, which make it catch on firmly by several points of attachment to passing animals. These are the kinds we human beings of either sex oftenest find clinging to our skirts or trousers after a walk in a rabbit-warren. But in herb-bennet and avens each nut has a single long awn, crooked near the middle with a very peculiar S-shaped joint, which effectually catches on to the wool or hair, but drops at the elbow after a short period of withering. Sometimes, too, the whole fruit is provided with prehensile hooks, while sometimes it is rather the individual seeds themselves that are so accommodated. Oddest of all is the plan followed by the common burdock. Here, an involucre or common cup-shaped receptacle of hooked bracts surrounds an entire head of purple tubular flowers, and each of these flowers produces in time a distinct fruit; but the hooked involucre contains the whole compound mass, and, being pulled off bodily by a stray sheep or dog, effects the transference of the composite lot at once to some fitting place for their germination.

Those plants, on the other hand, which depend rather, like London hospitals, upon the voluntary system, produce that very familiar form of edible capsule which we commonly call in the restricted sense a fruit or berry. In such cases, the seed-vessel is usually swollen and pulpy: it is stored with sweet juices to attract the birds or other animal allies, and it is brightly coloured so as to advertise to their eyes the presence of the alluring sugary foodstuff. These instances, however, are now so familiar to everybody that I won’t dwell upon them at any length. Even the degenerate schoolboy of the present day, much as he has declined from the high standard set forth by Macaulay, knows all about the way the actual seed itself is covered (as in the plum or the cherry) by a hard stony coat which ‘resists the action of the gastric juice’ (so physiologists put it, with their usual frankness), and thus passes undigested through the body of its swallower. All I will do here, therefore, is to note very briefly that some edible fruits, like the two just mentioned, as well as the apricot, the peach, the nectarine, and the mango, consist of a single seed with its outer covering; in others, as in the raspberry, the blackberry, the cloudberry, and the dew-berry, many seeds are massed together, each with a separate edible pulp; in yet others, as in the gooseberry, the currant, the grape, and the whortleberry, several seeds are embedded within the fruit in a common pulpy mass; and in others again, as in the apple, pear, quince, and medlar, they are surrounded by a quantity of spongy edible flesh. Indeed, the variety that prevails among fruits in this respect almost defies classification: for sometimes, as in the mulberry, the separate little fruits of several distinct flowers grow together at last into a common berry: sometimes, as in a fig, the general flower-stalk of several tiny one-seeded blossoms forms the edible part: and sometimes, as in the strawberry, the true little nuts or fruits appear as mere specks or dots on the bloated surface of the swollen and overgrown stem, which forms the luscious morsel dear to the human palate.