This little chine, opening toward the sea through the blue lias cliffs, has been worn to its present pretty gorge-like depth by the slow action of its tiny stream—a mere thread of water in fine weather, that trickles down its centre in a series of mossy cascades to the shingly beach below. Its sides are overgrown by brambles and other prickly brushwood, which form in places a matted and impenetrable mass: for it is the habit of all plants protected by the defensive armour of spines or thorns to cluster together in serried ranks, through which cattle or other intrusive animals cannot break. Amongst them, near the down above, I have just lighted upon a rare plant for Southern Britain—a wild raspberry-bush in full fruit. Raspberries are common enough in Scotland among heaps of stones on the windiest hillsides; but the south of England is too warm and sickly for their robust tastes, and they can only be found here in a few bleak spots like the stony edges of this weather-beaten down above the chine. The fruit itself is quite as good as the garden variety, for cultivation has added little to the native virtues of the raspberry. Good old Izaak Walton is not ashamed to quote a certain quaint saying of one Dr. Boteler concerning strawberries, and so I suppose I need not be afraid to quote it after him. 'Doubtless,' said the Doctor, 'God could have made a better berry, but doubtless also God never did.' Nevertheless, if you try the raspberry, picked fresh, with plenty of good country cream, you must allow that it runs its sister fruit a neck-and-neck race. To compare the structure of a raspberry with that of a strawberry is a very instructive botanical study. It shows how similar causes may produce the same gross result in singularly different ways. Both are roses by family, and both have flowers essentially similar to that of the common dog-rose. But even in plants where the flowers are alike, the fruits often differ conspicuously, because fresh principles come into play for the dispersion and safe germination of the seed. This makes the study of fruits the most complicated part in the unravelling of plant life. After the strawberry has blossomed, the pulpy receptacle on which it bore its green fruitlets begins to swell and redden, till at length it grows into an edible berry, dotted with little yellow nuts, containing each a single seed. But in the raspberry it is the separate fruitlets themselves which grow soft and bright-coloured, while the receptacle remains white and tasteless, forming the 'hull' which we pull off from the berry when we are going to eat it. Thus the part of the raspberry which we throw away answers to the part of the strawberry which we eat. Only, in the raspberry the separate fruitlets are all crowded close together into a single united mass, while in the strawberry they are scattered about loosely, and embedded in the soft flesh of the receptacle. The blackberry is another close relative; but in its fruit the little pulpy fruitlets cling to the receptacle, so that we pick and eat them both together; whereas in the raspberry the receptacle pulls out easily, and leaves a thimble-shaped hollow in the middle of the berry. Each of these little peculiarities has a special meaning of its own in the history of the different plants. Yet the main object attained by all is in the end precisely similar. Strawberries, raspberries, and blackberries all belong to the class of attractive fruits. They survive in virtue of the attention paid to them by birds and small animals. Just as the wild strawberry which I picked in the hedgerow the other day procures the dispersion of its hard and indigestible fruitlets by getting them eaten together with the pulpy receptacle, so does the raspberry procure the dispersion of its soft and sugary fruitlets by getting them eaten all by themselves. While the strawberry fruitlets retain throughout their dry outer coating, in those of the raspberry the external covering becomes fleshy and red, but the inner seed has, notwithstanding, a still harder shell than the tiny nuts of the strawberry. Now, this is the secret of nine fruits out of ten. They are really nuts, which clothe themselves in an outer tunic of sweet and beautifully coloured pulp. The pulp, as it were, the plant gives in, as an inducement to the friendly bird to swallow its seed; but the seed itself it protects by a hard stone or shell, and often by poisonous or bitter juices within. We see this arrangement very conspicuously in a plum, or still better in a mango; though it is really just as evident in the raspberry, where the smaller size renders it less conspicuous to human sight. It is a curious fact about the rose family that they have a very marked tendency to produce such fleshy fruits, instead of the mere dry seed-vessels of ordinary plants, which are named fruits only by botanical courtesy. For example, we owe to this single family the peach, plum, apricot, cherry, damson, pear, apple, medlar, and quince, all of them cultivated in gardens or orchards for their fruits. The minor group known by the poetical name of Dryads, alone supplies us with the strawberry, raspberry, blackberry, and dewberry. Even the wilder kinds, refused as food by man, produce berries well known to our winter birds—the haw, rose-hip, sloe, bird-cherry, and rowan. On the other hand, the whole tribe numbers but a single thoroughgoing nut—the almond; and even this nut, always somewhat soft-shelled and inclined to pulpiness, has produced by a 'sport' the wholly fruit-like nectarine. The odd thing about the rose tribe, however, is this: that the pulpy tendency shows itself in very different parts among the various species. In the plum it is the outer covering of the true fruit which grows soft and coloured: in the apple it is a swollen mass of the fruit-stalk surrounding the ovules: in the rose-hip it is the hollowed receptacle: and in the strawberry it is the same receptacle, bulging out in the opposite direction. Such a general tendency to display colour and collect sugary juices in so many diverse parts may be compared to the general bulbous tendency of the tiger-lily or the onion, and to the general succulent tendency of the cactus or the house-leek. In each case, the plant benefits by it in one form or another; and whichever form happens to get the start in any particular instance is increased and developed by natural selection, just as favourable varieties of fruits or flowers are increased and developed in cultivated species by our own gardeners. Sweet juices and bright colours, however, could be of no use to a plant till there were eyes to see and tongues to taste them. A pulpy fruit is in itself a mere waste of productive energy to its mother, unless the pulpiness aids in the dispersion and promotes the welfare of the young seedlings. Accordingly, we might naturally expect that there would be no fruit-bearers on the earth until the time when fruit-eaters, actual or potential, arrived upon the scene: or, to put it more correctly, both must inevitably have developed simultaneously and in mutual dependence upon one another. So we find no traces of succulent fruits even in so late a formation as that of these lias or cretaceous cliffs. The birds of that day were fierce-toothed carnivores, devouring the lizards and saurians of the rank low-lying sea-marshes: the mammals were mostly primÆval kangaroos or low ancestral wombats, gentle herbivores, or savage marsupial wolves, like the Tasmanian devil of our own times. It is only in the very modern tertiary period, whose soft muddy deposits have not yet had time to harden under superincumbent pressure into solid stone, that we find the earliest traces of the rose family, the greatest fruit-bearing tribe of our present world. And side by side with them we find their clever arboreal allies, the ancestral monkeys and squirrels, the primitive robins, and the yet shadowy forefathers of our modern fruit-eating parrots. Just as bees and butterflies necessarily trace back their geological history only to the time of the first honey-bearing flowers, and just as the honey-bearing flowers in turn trace back their pedigree only to the date of the rudest and most unspecialised honey-sucking insects, so are fruits and fruit-eaters linked together in origin by the inevitable bond of a mutual dependence. No bee, no honey; and no honey, no bee: so, too, no fruit, no fruit-bird; and no fruit-bird, no fruit. |