Dec. 23, 1881.] 



. KNOV/LEDGE ♦ 



153 



©rigiual woodland family of Oriental climbers. Yet, after 

 all, we have only been able to carry a little further, by 

 careful selection and tillage, the peculiarities which Nature 

 had long since produced in the priniiti\ e native stock. At 

 best, man can only develope more fully what the plant itself 

 has well begun. Our ornamental flowers are but the hand- 

 somest chosen wild blossoms ; our cereals and edible roots 

 are but the starchiest wild seeds and tubers ; and our 

 garden fruits are but the pick of the hips and haws 

 and wayside berries, improved and altered by ages of 

 cultivation. 



The grape-vine, they say, comes to us originally from 

 the shores of the Caspian. Even in its nati\e condition it 

 produces little sweetish acid grapes, hanging in purple 

 clusters among its green festoons. The question is, then, 

 of what use to the plant itself are thest; juicy fruits ? 

 For we now know that whate\er use nan may make of 

 this, that, or the other organ in any particular plant or 

 aoimal is, so to speak, an accidental after-thought ; the 

 organ always subserves besides some useful purpose in the 

 economy of the plant or animal itself to which it belongs. 

 Now, of course, tlie main use of all fruits is to produce 

 or contain the seeds. They are merely seed-vessels, and, 

 in most cases, they are dry and brown when ripe, like 

 the pea-pod, the poppy-head, or the capsule of the mig- 

 nonette. The problem we have to answer in the case of 

 the grape is therefore this : Why should it be pulpy and 

 prettily coloured, while these other fruits — and, indeed, the 

 vast majority of all fruits — are mere dry and unattractive 

 organs t 



The analogy of red and white and yellow flowers aflbrds 

 us a good hint towards the solution of this problem. "We 

 know that flowers have acquired their bright hues, their 

 honej', and their perfume, for the sake of attracting the 

 insects which fertilise them by carrying pollen from head 

 to head. Is there any way in which fruits can similarly 

 benefit by alluring the eyes of any anitnal race 1 At first 

 sight this would seem impossible ; but a little consideration 

 vrill show us a way out of the difliculty. Most plants, it is 

 true, can only lose by allowing their seeds to be perceived 

 and eaten by animals. In such cases the fruit, be it pod 

 or capsule, is usually inconspicuous in colour, and drops 

 its tiny little seeds quietly out upon the ground beneath. 

 Those plants which best succeed in diverting the attention 

 of seed-eating birds or mammals from their fruits, outlive, 

 in the long run, their less adapted neighbours ; and so the 

 survival of the fittest has brought it about that ninety- 

 nine kinds out of a hundred in our own da)' have unnotice- 

 able little green or brown seed vessels, such as those of the 

 chickweed, th.e pimpernel, and the clover tribe, which no- 

 body but a botanist ever observes at all. Suppose, how- 

 ever, that any plant happens to have its seeds covered 

 ■with a moderateh hard and indigestible outer coat, would 

 it not then be rather benefited than otherwise by having 

 these seeds enclosed in a .soft antl juicy bed of edible pulp 1 

 For in that case birds and other animals might eat the 

 seeds, fruit and all, for the sake of the pulpy covering ; and 

 as the hard little shell would protect the young embryo 

 ■within, this vital part would not be digested, but would 

 pass uninjured through the creature's body. By such an 

 arrangement the plant would not only get its seeds dis- 

 persed — in itself a most important matter — but would also 

 have the young seedling well manured and started in life 

 under unusually favourable auspices. ' If such a tendency 

 were ever to be set up even in the slightest degree by a 

 mere sport or chance variation, we may be sure tlie variety 

 in which it appeared would be so favoured by circum- 

 stances, that it would soon become a marked and distinct 

 species. 



As a matter of fact, it is pretty certain that such has 

 been the origin of all edible pulpy fruit.s. Take, foi' 

 example, these giapes here. If you cut one of them open, 

 you will find inside a number of hard little seeds. Slice 

 one of these again with a sharp penknife, and you will see 

 that it consists of a tiny embryo plant in the centre, sur- 

 rounded by a \ery solid bony shell. Each seed is in fact a 

 miniature nut ; and the kernel, so to speak, consists of th<' 

 tiny plautlet within, together with the albumen on which 

 it feeds when it first begins to germinate. Now, if any 

 bird were to swallow and digest this vital part of the seed, 

 the plant would, of course, be an obvious loser. But the 

 hard shell prevents such a catastrophe from happening ; 

 and, therefore, the plant is benefited by the soft, eatable 

 pulp which surrounds these little mimic nuts. Observe, 

 too, that the fruity part of the grape is sweet ; it contains 

 grape sugar. Now sugar is always laid up in those parts 

 of plants which specially seek to attract the animal world. 

 In flowers, the nectar allures the fertili-siug bees and butter- 

 flies ; in fruits and berries, the sweet juices allure the birds 

 which disperse the seeds ; nay, even the pitcher plants 

 secrete honey to wile flics into their insect-eating cups ; and 

 certain acacias store it up in hollow thorns to attract the 

 epicurean ants, wliich, in turn, protect the tree by driving 

 away their leaf-eating relations. In almost every case, one 

 may say that where sugar is found in any organ of a plant, 

 it is placed there for the sake of engaging the attention of 

 some animal ally ; while conversely, all flower-feeding and 

 fruit^eating creatures always manifest a marked taste for 

 sweet substances, dependent upon their long habituation to 

 sugary food. 



Not only, however, are the grapes sweet, but they arc 

 also brightly coloured. Naturally, among succulent fruits 

 bidding for the attention of birds, those would best succeed 

 which were most visible at some little distance. Ac- 

 cordingly, just as the insect-fertilised flowers have developed 

 brilliant pigments in their petals, so the fruits which 

 depend upon birds for the dispersion of their seeds have 

 acquired prettily-coloured coverings. We all know how 

 noticeable are the hips and haws, the holly-berries and 

 rowan-berries, even among our northern woodlands ; while 

 the oranges, mangoes, and pomegi-anates of the tropics 

 appeal even more vividly to the sharp eyes of monkeys, 

 parrots, and toucans. At the same time, it is noteworthy 

 that the tastes of birds with regard to colour seem to difiei' 

 somewhat from those of insects ; for, as jStr. Wallace 

 points out, white, which is a common colour for flowers, is 

 rare among fruits ; while piu'ple and bluish-black, which 

 are seldom met with among flowers, may almost be con- 

 sidered as the ordinary colours of most wild fruits. 



Looking closely into my cluster of grapes, again, I see 

 that it still contains two or three imripe and stunted 

 specimens. These, of course, are pale-green, like the 

 leaves, and when I taste one of them I find it unpleasantly 

 harsh and at id to the palate. This reminds me that grapes, 

 like other fruits, are not at all stages of their existence 

 sweet and brightly coloured. While the seeds are still 

 immature, they would only lose by Ijeing eaten, because 

 they are not yet fit for germination. In this stage, there- 

 fore, the skin is filled with green colouring mattei-, and the 

 cluster is quite inconspicuous among the foliage which 

 surrounds it. It does not want to attract attention in its 

 present stage. Furthermore, the pulp at this period is 

 filled with tai*taric acid and other sour juices, to repel any 

 too-inquiring or too-impatient visitor. But as the seeds 

 mature, the fruit ripens — that is to say, a chemical change 

 goes on in the pulpy portion, which results in the formation 

 of grape-sugar. At the same time, other chemical changes 

 taking place in the skin result in the production of the 



