EFFECTS OF CULTURE ON VEGETATION

New Zealander, Volume 3, Issue 170, 15 January 1848, Page 3

EFFECTS OF CULTURE ON VEGETATION

The effect produced by civilization on the feelings and intellect of the savage, the modifications induced in the characters of the lower animals by domestication, are not more wonderful than the changes which have been effected on many vegetable families by the power of cultivation. Root, stem, leaf, flower, and fruit, are each naturally'endowed with a certain degree of mutability, according to circumstances of soil, climate, and other external conditions— and man, practising upon tbis mutability, hat in course of time succeeded in i earing products which bear scarcely any resemblance to their natural originals. There is a limit, no doubt, to this divergence from the normal type— a line beyond which organic adaptability cannot be forced without interfering with the healthy existence of the organiim ; /Cut of such a limit in vegetation we are yet almost absolutely ignorant. All that can be said in the present state of our knowledge is, that certain remits have been obtained, some of which we intend to notice as being at once curious and important. In a state of nature, most vegetable tribes are limited to definite localities, these situations being characterized by some peculiarity of soil and atmospheric infill•ence. If the conditions of soil arid climate remain the same, the character of plants is nearly uniform and stationary— and this may be always said of them in their natural state. But if they be removed from a poor to a rich soil, from a waim to a cold climate, from a dry to a moist habitat, or vice versa, then their internal structure will undergo a change, and this change will manifest itself in one or ther of their external characters. In some classes, the change is most evident in the roots and tuben, in Others in the stems and loaves —while in many, the. flowers and fruit are the parts

mo9t affected. Sometimea'change of situation produces merely a more luxuriant developement of all the parts of a plant, without causing any abnormal growth of a particular organ, as may be seen every season by comparing the crops on a poor gravelly soil with those on a rich alluvium, or the produce of a neglected fieU with that of a well-manured garden. Culture, in the widest sense of the word, may therefore be considered as the cause of these irregulur changes, which assume in plants a wonderful degree of permanence, and may be transmitted to succesiive races ; though generally speaking, if the artificial stimulus be not kept up, plants will leturn to their normal or natural condition. The changes which roots and tubers can be made to undergo are numerous, and highly beneficial to man. The potato, for example, is a native of tropical America, andjwhen found wild, itstuberi are not laiger than a chestnut, and scarcely edible — while in Europe it has been rendered, by artificial treatment, one of the most valuable articles of human food. The produce of an acre of wild potatoes could be held in a single measure -—while in Britain the same area will yield from forty to sixty bolls. Cultivation has also produced innumerable varieties of this tuber, each varying in size, shape, color, and quality, and this, it may be said, all within the last hundred years— for though the potato was imported from America three centuries ago, it is icarcely one since it met with anything like attention. Beet, parsnip, and turnip, have been also wonderfully modi ■ fled by culture, and made to break off into numerous varieties. The bulb of the latter, for instance, has, since the beginning of the present century, been metamorphosed from globular to fusiform, in colours from white and yellow, to purple and green, and in weight fiorn a couple of ounces to more than twenty pounds. So also with the carrot, which in a wild state has a slender root of a yellowish-white color, but which, under cultivation swells out, and becomes succulent, assuming a deep red or orange color. In the one case the root is not much thicker than a common quill, in the other it becomes as thick and long as a man's arm — the produce being sometimes so much as 400 bushels per acre. The cause of most of these changes is abundantly obvious. Cultivation removes a plant to a richer soil, where'it can obtain all the elements essential to its growth with greater facility, and without suffering those impediments to continuous growth which alternate drenchings and droughts arc bo apt to occasion in a state of nature. It the soil be too wet it undergoes drainage— if too dry it is irrigated— besides being deepened and softened to admit of the easy expansion of the bulb or tuber on every side. As in animals, so in plants, every individual has a tendency to reproduce its own qualities m its offspring, and man, taking advantage of this feature, rears only such species and hybrids as best suit his purpose, until by successive developments, these qualities greatly exceed anything in nature, or even become altogether monstrous. Stems, though less liable to metamorphoses of this kind, are still capable of being strangely changed from their normal condition. Every one is aware that if a tree which is a native of mountains be planted in a villey, it grows more rapidly, but its timber becomes softer and less durable ; and m like manner, if the tree of a valley be removed to a mountain, it becomes of slow growth and stunted form, but produces timber remarkable for its toughness and durability. By cultivating upon this principle, tall stems are for the most part rendered short or dwarfish, and shorter ones taller — the dahlia, for example, having been reduced to one half of its natural height by garden culture. The cabbage, iv a wild state, had a tough, slender stem, which by culture lias become fleshy and fusiform : there are no stalks and shoots to be found among the asparagus plant of the sea-shore which can compare with those of our gardens ;, and so also it might be noted of many culinary plants, wh eh differ so much from their originals, that none but a botanist could detect the relationship. Nor is it in the external characters only that cultivation effects Buch changes : the intrinsic properties are equally liable to metamorphosis— as from sour to sweet, from acrid to agreeable, or even from poisonous to wholesome. The well-known garden celery is* a native biennial found on the sides ot ditches in the vicinity of the sea, and in this state is highly acrid, and of a coarse rank flavour. Culture, however, has now transformed the leaf-stalks of the common species into one of the most agreeable salads, and the bulbous roots of the celeriac into a wholesome and nutritious esculent. As in roots and stems, so in leaves, the influence of cultivation is manifested in a very marked and curious manner. * The Brassica oleracta,' says Dr. Neill, 'is a plant indigenous to our rocky shores ; but no one seeing it waving its foliage in its native habitat, could possibly anticipate that it would ever appear in our gardens disguised as the ponderous drum-head or sugar-loaf cabbage, or on our tables as the delicate cau i flower and broccoli.' In the one case the stem is tough and slender ; in the other it becomes fleshy and fusiform ; when wild, the leaves are small and wavy ; under favourable culture they become large and succulent, thickening so rapidly, that they have not actually room t) unfold themselves, but gather into a heart or duster several feet in circumference. The original olewort would weigh scarcely half an ounce ; we have seen a well-nourished drum-head weigh more than thirty pounds. The Crambe maritima, another plant growing spontaneously on the southern shores of our itland, has in like manner been improved into the seakale of our markets : so it maybe remarked of the artichoke, the endive, spinach, and , in fact, of all our esculents and salads. It is owing to this protean suscep tibility that, under cultivation, certain leaves become pucttercd, as in the curled cress and curled savoy ; that notched and lobed ones become simple nnd entire ; and that thin and leathery ones are transformed into thick and succulent masses. The changes which occur in the floral organs are also very numeruous ; and on this feature depends all that beauty and variety which it is now so much the object of the floiist to produce. These transformations consist in an increase of the petals, in a conversion of petals into stamens, and in some modification of the colour. What are called double flowers are produced by a multiplication of the petals, as in the common varieties of che rose ; and full flower* are those in which the multiplication is carried so far as to obliterate the stamens and pistils. The rose, for example, produces in a wild state only a single row of petals surrounding a vast number of yellow stamens ; but when cultivated, many rows of petals are formed at the expence of the stamens, which are proportionally diminished in number. Compare the dog-rose of our hedges with the cabbage or Provence rose of the garden ; or compare the single anemones ami ranunculuses oi the Levant with the finest Dutch varieties, and see what cultivation has produced. In the one case there are only five diminutive petals ; in the other we have hundreds : the wild anemone is scarcely an inch across ; Dutch florists have reared specimens more than six inches in diameter. The same may be remarked of the polyanthus, which is very unlike its parent, the primrose ; of the auricula, the haycinth, dahlia, and other floral favourites, which, under cnltiration, have each sported into many hundred varieties* ' The dahlia,' says a recent authority, ' is a native of Mexico, from which it was introduced in 1789, but afterwards ost to our cultivators. It was r.eintro.duccd in. 1804 j

but it was not till ten years later that it was generally known in our gardens. The first pants were single, of a pale purple colour, and though interesting, as affording a new form of floral ornament, they by no means held forth the infinite diversity of that tint and figure exhibited by their double- flowered successors. At present the varieties aie endless, each district of the country possessing suites of its own, and cultivators occasionally raising at one sowing a dozen kinds which they think worthy of preservation. Ths results have been most propitious to the flower-garden, from which, indeed, the dahlia could now nearly as ill be spared as the potato from the kitchen-garden.' With regard to the change of hues in the colouring of flowers — the streakings, the mottlings, and dashiugs —it is almost impossible to speak. ' It's infinite changes and metamorphoses in almost every cultivated flower,' says Dr. Lindley, ' can be compared to nothing but the alterations caused in the plumage of birds, or in | the hairs of animals by domestication. No cause has ever been assigned to these phenomena, nor has any attempt been made to determine the cause in plants. We are, however, in possession of the knowledge t of some of the laws under which change of colour is effected. A blue flower will change to white or red, but not to bright yellow ; a bright yellow flower will become white or red, but never blue. Thus the hyacinth, of which the primitive colour is bluei produces abundance of white and red varieties, but nothing that cap be compared to bright yellow— the yellow hyacinths, as they are called, being a sort of pale yellow ochre, verging to green. Again, the ranunculus, which ii originally of an intense yellow, gporti into scarlet, red, purple, and almost any colour but blue. White flowers wbich have a tendency to produce red, will never sport to blue, although they will ! to yellow — the roses, for ejample, and the crysanthemums.' A few scanty observations such as these are all that can yet be offered by the naturalist respecting a subject which gives to many plants their sole value, and to all vegetation one of its chief attractions. The changes produced by cultivation in the jruit or | teed ate also very numerous and obvious. Where, for instance ( is theie a native grain like wheat, or a native fruit like the apple ? In a wild state, the seeds of our cereal grains (wheat, barley, oats,) &c. are thin and [ meagre : under proper culture, they become large, plump, and full of faiina, so as to afford the most important elements of human subsiitance. The small globular sour crab of our hedges is the original of the numberless varieties of apples now cultivated in our orchards, each variety differing somewhat in size, shape colour, and flavour. In like manner with the sloe, which few could detect as the parent of our purple; yellow, and white plums ; with the hazel-nut, which is the ancestor of the filbert and cub-nut ; with the almond, which is the original of the peach and nectarine ; with the diminutive wild lime, from wkich hus sprung the shaddock, the orange, and lemon j and so also the wild cherry, and with almost every species of our cultivated fruits. We not only can change their size, colour, and other external characters, but can transform them from dry, acrid, and noxious fruits, to fleshy, pleasant, and wholesome products. The above are some of the more obvious and important effects produced by the ingenuity of man on the natural characters of plants, especially as exhibited in the roots, stems, leaves, and organs of fructification. We could add almost indefinitely to the list ; but enough has been advanced to show that vegetation ii endowed with a wide lange of adaptability — a feature necessary, in the first instance, for its own preserva* tion against the vicissitudes of soil and climate, to which it may be subjected ; and evidently fitted in a secondary sense, to administer more fully to the growing requirementi of civilised man. The results which have been accomplished refer but to an insignificant section of the vegetable races ; and judging from these, we may be hopeful that tkere are yet thousands of species equally fitted, under cultivation, to administer to our support and gratification. — Chambers Journal.

Extraordinary Accident. — On Monday last an accident of an extmoriinary nature occurred og board the Nelson, at Williams Town. This vessel is loading wool for London, and the men employed in loading her. alter putting in a tier o f wool, as tight as it could be got in, proceeded, as is usual, to put the jack screws in for the purpose of jambing the bales tightly to the sides of the ves«<el, to muke room for two or more bales ; those acquainted with the process will understand it by the term of " reeding off." At the time this operation is going on, it is calculated, enourmous as it may appear, that here is a pressure of not less than one hundred tons upon the wool, and in the present instance, so great was the pressure, that the end of the jack screw went through the piece of timber which is placed upon the bail, and which is operated upon by the icrew, which not only fairly penetrated the wood, but the wool also. Tue consequence of the accident was, that the wool immediately collapsed upon the four mea who were in the hold, employed in working the screws, but luckily at the same moment the jack-screws canted over, creating a small vacuum between the bales, otherwise instantanious death must have.ensued to the whole of the parties ; they were w th great difficulty released from their perilous situation, when it was discovered that one unfortunate man had got his j.iw smashed by coming into violent contact with the lever of the screw ; lock jaw ensued, and if his sufferings be not already terminated by death, no anticipations are entertained of his recovery ; another one had his foot laid completely back upon his shin, bone and the other two escaped with a few bruises. Altogether the escape may be looked opon as most mira« culous, in fact, had the jack-icrewi fallen into any other position than that they fortunately did, nothing ould have saved the whole of the unfortunate men from being crushed to death.— Melbourne Argus, Dec. 10 Experiments at Woolavich.— Some very interesting experiments are now being made at Woolwich on the comparitive strength of guns of different construction, in order tv ascertain the most effective distribution of a given weight of metal. The guns now under trial are 32-pounden, weighing just 50 cwt. each. Two of these gum have been fired till they burst, and the remit it as follows :— Mr. Monk's gun stood altogether 130 rounds, the charges progressively increasing from 81b. of powder with two snot and two wads, to 121b. of powder with three shot and three wads ; md it burst on the 131 round. The gun of Colonel Dundai's pattern stood 140 rounds, with similar progressively increasing charge* ; and it burst on the 141 st round, the last round being fired with i 31b. of powder, three shot aud three wads having stood 10 rounds more that the other gun, with 12ib. of powder and threble-shoted. Tbe experiments are still proceeding with other guns, and it is considered that they will decide the important question which has long been agitated, as to the weight of metal i* a gun, so as to combine the greatest strength with the greatest lightness.— Glil/e. Were women allowed t) plead in Courts of judicature, I am persuaded they would carry the eloquence of the bar to greater heights than it has act arrived at* If any one doubt this, let him be but present at those debates which frequently arise among the ladies of the £ritis.h nailery.