These three fields are situate on the Agricultural College Farm, the substrata of which are forest marble and great oolite, and 2 and 3 were absolutely adjoining each other. How different, then, are the species of wild plants in fields so close together, when out of a list of sixty-four species only twenty-four, or a little more than one-third, are common to all three of the fields examined; and yet we can safely affirm that the aboriginal flora of any three fields of thedistrict would scarcely offer half a dozen species in the one field that could not be found in all; and, indeed, in a field that had lain fallow for several years not half of the present list would be found.
That these, then, have to a great extent been sown with the seed is quite certain; but what tends further to strengthen the argument is, that theVeronica Buxbaumii(Buxbaum’s Speedwell) and thePetroselinum segetum(Corn Parsley) are not native to the farm; and, indeed, it is doubtful whether very many of our agrarian weeds are true natives, as on examination many weeds will only be found in special crops, and these occur in the same crops all over the world wherever those crops can be cultivated. Our own country, then, has, doubtless, imported a large portion of her weed flora from abroad, just as we have traced in the United States, European (not American) plants, tracking the settlers from England, Ireland, and Scotland. It is thus that the European daisy (Bellis perennis) has got the name of the “White Man’s Foot.”
Seeing, then, that the clover seeds are so liable to be dirty, it becomes an important inquiry as to whether it is possible to get pure seed; and in reply to this query we should answer, from a long experience, that though one seldom sees pure clover seed, yet it sometimes falls in our way, or at least so pure that its weeds are reduced to a minimum. Such samples may be expected to be high-priced; but still, how much cheaper than a dirty article!—for, independently of having only the seed of the crop you wish to cultivate, you are saved the annoyance which must arise when a weed has taken root, in thatthen the clover cannot grow, and you ultimately see the ground occupied by a spreading noxious plant, or, this dying out, there will be a vacant spot,—in either case resulting in a loss of nutriment.
But, besides the more natural method of selling dirty seed from weedy patches, seedsmen are too apt to mix the seed of plantain (Plantago lanceolata) with that of clover; for, as the colours of the seeds are not unlike, and some people speak favourably of plantain as a sheep-feed, it is unblushingly mixed and sold with clover seed, though the plantain at most is only worth about half the price.
Where it occurs naturally amongst clovers, it may be separated to make a good sample, but only to be ultimately mixed again and sold to greenhorns with a cheap sample. We have had before us samples of clover containing plantain as under:—
In the instance where we had estimated as many as 1,568,000 plantain seeds to a bushel of clover seed, the seedsman admitted that he had put it with the clover at the rate of one pound of plantain to eleven pounds of clover, under the impression that it was a desirable pasture plant. Now this we know is oftendone; but is it not always charged for as clover in cases where it is used for adulteration?
This matter, then, of dirty seed is clearly one of importance: it, however, only wants the farmer to become acquainted with the true form of clover seed to enable him to detect any admixture in this; and then, if he has this knowledge, so requisite for his well-doing, and steadily abstains from purchasing the nasty, however cheap, he will soon find that his seedsman will supply him with a genuine article, which, all things considered, will be even cheaper than the opposite.
Of the truly parasitic plants affecting the clover crop, we have two genera—namely,Cuscutaor Dodder, andOrobancheor Broomrape. Both of these, some few years since, were comparatively rare as farm pests; but as they are probably more abundant on Continental than on our home farms, they are greatly increasing from the constant influx of foreign seeds.
Of the genusCuscutawe have two species of agricultural importance,—Cuscuta epilinum, the Flax Dodder, andC. trifolii, the Clover Dodder. In both, the plant itself consists of a mass of pink and yellowish tendrils, upon which are placed here and there compact bunches of flowers varying alike in colour. The whole plant, in both species, being entirely parasitic—that is, it lives wholly on the juices of its foster-parent,—it has no leaves of its own; still, however, the Dodder plant is in the first instance produced from seed, each flower being succeeded by a capsule containing two small wrinkled seeds, which, not being larger or lighter in theC. epilinumthan a linseed, or in the still smaller seed of the clover, in the case of theC. trifolii, the seed of flax or clover crops affected with dodder will never be entirely free from it: as an evidence ofits large increase, we remember once seeing a crop of flax grown from Riga seed diminished about one-twentieth by the dodder; but on the seed so produced being sown in another field of the same farm, the crop of flax was well-nigh destroyed.
Our friend Professor Voelcker had some seed of the flax dodder sent to him for analysis, the reason being that, as his correspondent had separated a great number of bushels of this weed pest from a single crop of flax, he was desirous of ascertaining whether it possessed any feeding properties or the reverse; and on this head it is satisfactory to learn that it is considered useless, though innocuous.
It was part of this sample with which we experimented on the mode of growth of dodder, which, although being the dodder of the flax or linseed plant, yet its natural history will doubtless be that of the clover dodder;[8]we shall, therefore, describe the progress of our experiments, and their results.
[8]We are desirous of instituting special experiments on the growth of clover dodder, but have failed to procure ripe seed, the reason being that the seed does not ripen after the clover has been cut down for its first crop.
[8]We are desirous of instituting special experiments on the growth of clover dodder, but have failed to procure ripe seed, the reason being that the seed does not ripen after the clover has been cut down for its first crop.
Germination of flax dodderA. Seed-covering beneath whichradicleor young root is pushing.B. Leafless stem or tendril growing upwards, bearing seed-covering on its apex.C. Young thread-like plant freed from seed-covering, on the look-out for a foster-parent.D. Not finding a foster-parent, droops and dies.
A. Seed-covering beneath whichradicleor young root is pushing.B. Leafless stem or tendril growing upwards, bearing seed-covering on its apex.C. Young thread-like plant freed from seed-covering, on the look-out for a foster-parent.D. Not finding a foster-parent, droops and dies.
Having prepared some finely-sifted soil in a garden saucer, we sowed a small quantity of flax seed with which had been purposely mixed a few of the seeds of flax dodder; this, on being placed in a hot-house, showed the progress indicated in thediagram.
Our nextdiagramshows the progress of dodder-growth when the parasite has germinated sufficiently near to a young flax plant to be attracted to it. In such case, instead of dying, it seems all at once to be animated by new vigour. The highly elastic thread, which now represents the whole dodder plant, goes through the following stages:—
Dodder-growthA. The dodder, having just clasped a flax plant, has made two coils round the stem of the latter.B. Meanwhile the flax in growing lifts the dodder out of the soil.C. While the flax is getting still taller, the dodder sends out rootlets, which pierce and fix themselves into the flax. During this the dodder sends out buds upwards, which, elongating until new flax plants are met with, explains not only how the dodder commences a growth quite independent of the soil, but, by spreading, from plant to plant, thus increases to an indefinite extent.
A. The dodder, having just clasped a flax plant, has made two coils round the stem of the latter.B. Meanwhile the flax in growing lifts the dodder out of the soil.C. While the flax is getting still taller, the dodder sends out rootlets, which pierce and fix themselves into the flax. During this the dodder sends out buds upwards, which, elongating until new flax plants are met with, explains not only how the dodder commences a growth quite independent of the soil, but, by spreading, from plant to plant, thus increases to an indefinite extent.
In this way, then, the dodder of flax, commencing from seeds at different points, spreads in more or less extended patches, which, if such centre be few, will be distinct; if many, the pest may occupy the greater part of the crop by spreading, and so becoming confluent.
Such is the method of growth of flax dodder, andwe have no doubt but that the dodder of the clover progresses in like manner; at all events, we see the latter occupying more or less isolated patches in the affected crop; and in this case, as in the former, the crop-plant is not only starved, from having “its verdure sucked out,” but it is borne down to the ground and ruined.
As regards its destruction, we should be careful to look at our crops in their early growth, as, if the sickly-looking, wire-like tendril be observed then, it is easily removed by hand; if, however, it has made head, the best way would be to make a trench of a foot wide around the plague-spots, which will prevent its spreading, as the plant must have contiguous clovers to twist round if it is to extend; and then burn some straw on the dodder plot, and it will be wasted to death. Probably, however, the easiest plan is to depasture the crop,—certainly not to seed it down—in which case it will be impossible for any dodder seeds to ripen.
But here, as in other cases, the evil will be prevented by sowing pure seed, whether of flax or of clover; and as the dodder is a small, brown, roundish little seed, so different from that of either crop, there is no difficulty in recognizing it where present.
The Broomrape is now becoming a very pernicious clover weed, especially in lighter soils. We have seen it on clover near Stonehenge so thick as to have positively spoiled the crop; and we should expect from its bitter, disagreeable flavour, that if cattle did not universally refuse to eat it, it might prove mischievous to them.
The species which attacks clover is theOrobancheminor—Lesser Broomrape,—which is at once distinguished in a clover field by its upright brownish spike of dead, dry-looking, lipped flowers; the stem without true leaves, but clothed with small brown leaf-like processes (bractsof the botanist), which, with the stem, are clothed with hairs.
This plant, which is much larger and very different from the clover, is parasitic on the principal division of the clover root; so that if the soil be carefully removed from the broomrape, it will be found to swell at the base, into which the clover root may be detected to be fastened, and a very odd appearance indeed has the small-stemmed clover united to so comparatively large a parasite.
The seeds of the broomrape are so small as scarcely to be detected in a sample of clover seed; indeed, several may be fastened to a seed as dust, so that whatever care may be used in the selection of seed will hardly prevent this pest. Any great injury to the clover crop may be speedily stopped by hand-picking the broomrape; for, although it will sometimes branch up again, it will be much lessened, and the few secondary shoots will usually be very weak.
Clovers are attacked byEpiphytes—that is, minute fungoid plants growing upon the leaves; but the natural history of these is too obscure for a general treatise, nor are they of sufficient interest to the practical farmer.[9]
[9]To such as may be interested in the study of the “rusts” of Clover, and some other plants, we would earnestly recommend a perusal of some most interesting papers on the subject, by M. C. Cooke, Esq., beautifully illustrated by Messrs. West & Sowerby, which will be found in thePopular Science Review—a serial which should have a place in the house of every country gentleman.
[9]To such as may be interested in the study of the “rusts” of Clover, and some other plants, we would earnestly recommend a perusal of some most interesting papers on the subject, by M. C. Cooke, Esq., beautifully illustrated by Messrs. West & Sowerby, which will be found in thePopular Science Review—a serial which should have a place in the house of every country gentleman.
CornCorn.
Corn.
By corn, in its enlarged sense, the farmer means all such crops as are grown for their seeds; so that all kinds of grain and pulse, such as peas and beans, belong to the corn crop, as distinguished from roots and green crops. In America the word “corn” is restricted to maize or Indian corn, and other crops are called after their respective names. Our dictionaries define corn as “seeds which grow in ears, not pods;” and it is to these that the present treatise is meant exclusively to apply, confining our remarks for the most part to such kinds as are more commonly cultivated in this country.
Corn, then, may be said to be derived from different species of grasses, whose seeds are sufficiently large to enable them to be threshed from the ear and become stored as grain, in which case it differs from the smaller kinds, whose seeds may be grown for pasturage crops.
Hence, then, grasses afford us two sets, which are differently used,—one, as affording corn fabled to bethe gift of the goddess Ceres, and so called cereal or corn grasses; the other, not grown for the sake of the grain, but for herbage, and named meadow and pasture grasses.
Corn grasses, then, belong exclusively to arable cultivation; and, indeed, it may be concluded that such have been derived from wild species, and that continued culture has brought them about, and still maintains them in all their endless varieties, and also gives us a power to add to these to an extraordinary extent.
It is this facility for improvement, this capability for forming grain on the one hand, and running into varieties on the other, which enables corn to be grown under so wide a range of temperature and in such varied and variable climates; and it is a knowledge of the laws affecting these changes, and the modes of action in the growth of corn consequent thereupon, which will constitute “Science and Practice in Corn Cultivation,” and should lead to a knowledge of “How to Grow Good Corn.”
In following out this inquiry, we shall, for the most part, confine our observations to the following crops:—
It is a popular belief that wheat, in a state fit for food, was a direct gift to man, and handed down to him unaltered in form, except in so far as relates to varieties; but if we consider how varied are the details of this plant, how very different from each other are the more remote varieties, and yet how easy it is to fill up the links on the one hand, or to arrive at equally distinct and yet new forms on the other, we can only conclude that wheat, like most, if not all, our vegetable esculents, is but aderivativeplant obtained from a wild form of grass, and in very early times brought into cultivation because of the facilities for change which it was capable of undergoing.
Nowhere is wheat, as such, found wild; for, although its grain has been cultivated in all parts of the world, its scattered seeds cannot maintain a position for any length of time; for, as it has been obtained by cultivation, so its derived status can only be maintained by careful culture, without which there seems reason to believe that cereal wheat would indeed become extinct.
Many botanists had arrived at these or kindred views from observation and reasoning upon the subject, but it was not until a comparatively recent period that we possessed any direct evidence derivedfrom experiment: this we now have, and upon it we quote the following from Mr. Bentham, in theCyclopædia of Agriculture, article “Triticum”:—
It has never been contended that their original types have become extinct, and various, therefore, have been the conjectures as to the transformations they may have successively undergone; and as no accidental returns towards primitive forms have been observed, we have till lately had but little to guide us in these vague surmises. Within the last few years, however, the experiments and observations of M. Esprit Fabre, of Agde, in the south of France, seem to prove a fact which had been more than once suggested, but almost always scouted, that our agricultural wheats are cultivated varieties of a set of grasses common in the south of Europe, which botanists have uniformly regarded as belonging to a different genus, namedÆgilops. The principal character by which the latter genus had been distinguished, consisted in the greater fragility of the ear, and in the glumes (i.e.the chaff-scales) being generally terminated by three or four, and the pales by two or three points or awns (beards). But M. Fabre has shown how readily these characters become modified by cultivation; and, wide as is the apparent difference betweenÆgilops ovataand common wheat, he has practically proved their botanical identity; for, from the seeds of theÆgilopsfirst sown in 1838, carefully raised in a garden soil, and re-sown every year from their produce, he had, through successive transformations, by the eighth year (1846) obtained crops of real wheat as good as the generality of those cultivated in his neighbourhood.
It has never been contended that their original types have become extinct, and various, therefore, have been the conjectures as to the transformations they may have successively undergone; and as no accidental returns towards primitive forms have been observed, we have till lately had but little to guide us in these vague surmises. Within the last few years, however, the experiments and observations of M. Esprit Fabre, of Agde, in the south of France, seem to prove a fact which had been more than once suggested, but almost always scouted, that our agricultural wheats are cultivated varieties of a set of grasses common in the south of Europe, which botanists have uniformly regarded as belonging to a different genus, namedÆgilops. The principal character by which the latter genus had been distinguished, consisted in the greater fragility of the ear, and in the glumes (i.e.the chaff-scales) being generally terminated by three or four, and the pales by two or three points or awns (beards). But M. Fabre has shown how readily these characters become modified by cultivation; and, wide as is the apparent difference betweenÆgilops ovataand common wheat, he has practically proved their botanical identity; for, from the seeds of theÆgilopsfirst sown in 1838, carefully raised in a garden soil, and re-sown every year from their produce, he had, through successive transformations, by the eighth year (1846) obtained crops of real wheat as good as the generality of those cultivated in his neighbourhood.
It was the description of the experiments of M. Fabre, in theJournal of the Agricultural Society, which led us to institute independent inquiries, to which end, having purchased some seeds ofÆgilops ovata, we sowed them in our experimental garden at Cirencester, in a prepared plot of five yards square, on a subsoil of forest marble. From this seeds were selected to carry on the experiments, whilst the mass of the plants in the plot were allowed to seed and come up spontaneously, which it did yearafter year, and so preserved the original type with which we started. The preserved seeds were sown in fresh plots year by year, but—perhaps owing to the coldness of the soil and the general lower climate of the Cotteswolds—progress was only slow at first; however, in the warm summer of 1859 our plot of the season had made fresh advances, which will be best understood by an examination of the accompanying drawings.
Fig. 3represents a spikelet of the type ofÆgilops ovata, introduced into our garden in 1855. In this some of the pales have double awns, others single ones.Fig. 4, a spikelet of 1859, modified by cultivation. In this the awns are single.Fig. 5, a spikelet from an ear of bearded wheat.
Now, the close affinity of these three forms must strike any one; but we feel justified in concluding that, had not our experiments been peremptorily stopped, and the results, as far as possible, spoiled from the ignorance and jealousy of the new Principal, we should before this have arrived at results much more satisfactory.
The principles of the observed changes will be understood by stating the following facts.
a.Ægilops ovatahas a seed of sufficient size to be called a corn grain, and which, though not so large as that of wheat, yet rapidly improves by cultivation, which includes selection.
b.Therachis(the part on which the spikelets are placed in the wild grass) is exceedingly brittle, so that it readily breaks into bits below each spikelet; this brittleness annually gets less under cultivation.
c.The wild grass has a trailing habit of growth; but uprightness and a longer culm is at once induced by the closer contact of drilling the seeds in thick rows.
d.The cultivation ofÆgilops, and especially subjecting it to rich soil, produces the same kinds of fungoid attacks as are found with wheats under like circumstances, as thus:—Puccinia graminis(mildew) of the leaves and culms;Uredo rubigo(red rust) of the chaff-scales;Uredo caries(smut or bunt) of the grain.
Now, all these circumstances seem to point to a similarity in essential structure, and a uniformity of habit somewhat remarkable in plants which at first sight would strike one as being so different; but as these differences betweenÆgilopsand any variety of wheat are often all scarcely greater than is to be met with on contrasting two known varieties of wheat, we may agree in concluding that the evidence warrants the assumption that wheat, as a cultivated cereal, has been derived fromÆgilops.
If, then, we view the wheat plant as a derivative, we shall be at no loss in understanding how the vast number of varieties have been brought about—varieties applicable, too, to a wide range of climatal conditions; and the ease with which new forms can be brought about by hybridization and selection is a matter of importance, because older varieties, too often repeated, are apt to degenerate both in quality of grain and quantity of crop. But when we speak of acclimatizing wheat, we think it would be excessively difficult to make any existing form grow well in a climate not congenial to it, though it might be easyto arrive at a new variety possessing some desired quality. We believe, however, that it is not difficult to alter a climate to suit a sort, and, in all probability, this at the present day much-used term of “acclimatization” simply means no more than making our cultivation and climate accord as nearly as possible to the habits of the plant or animal to be entertained under new conditions.
Thus, when we see the finer white wheats growing good crops on farms where such would have been impossible a few years ago, we are hardly to conclude that we have at length got this more delicate sort to become more hardy; but the climate has been ameliorated by draining and better cultivation.
We distinctly recollect when the lias clays of the Vale of Gloucester could scarcely be made to grow a good crop of even the hardier sorts of red wheat, the common cone being the sort generally grown. This was succeeded by many sorts of red wheat, and now only the best-cultivated farms produce white wheats. These, however, are facts which will be more strongly brought out when we consider the subject of cultivation; for the present we would be content with the expression of a belief that wheat, as a cereal grain, is derived by cultivation from a wild grass, and it is due to the effects of cultivation that we have so many sorts, with such variable adaptability.
Crop oats, like wheat, have ever been considered as a direct gift from Ceres, and few, indeed, amongst scientific men were willing to believe that they were derived from a wild and weed species. Still, the farmer had long maintained that oats, when cultivated, often left behind them weed oats; and in some districts of Worcester, Gloucester, and Warwick, we have known men refuse to grow oats as a crop from their fear of producing the terrible weed, which, indeed, the wild oat is on all hands admitted to be.
Now, although we by no means wish to advance the theory of transmutation, and cannot believe that by any plan barley can be converted into oats, or oats into barley, we are yet confident that what has been termedennobling, or the producing of a cultivated plant from a wild one, is oftentimes comparatively easy, and in none more so than in the production of crop oats from the wild species,Avena fatua.
Professor Lindley, in the article “Avena,” in Morton’sCyclopædia of Agriculture, suggests that the cultivated oat “is a domesticated variety of some wild species, and may be not improbably referred toAvena strigosa, bristle-pointed oat;” but our experiments would show that theAvena fatuais the formfrom which at least the domestic sorts in general cultivation seem to have sprung.
TheAvena fatua(wild oat) is an annual grass which almost universally accompanies agrarian circumstances; that is to say, it seldom, if ever, occurs in a truly wild aboriginal state, and is therefore not found in uncultivated tracts, but is the common attendant on tillage, and in some soils is a most common and disagreeable weed in various agricultural crops, but more especially amid grain, whether of wheat, barley, or oats. Sometimes it is found with beans, peas, and vetches, and, indeed, it may be said to be a common weed in some districts in any crop from which it has not been eradicated by the hoe—an operation almost impossible in grain, as its growth is so much like that of the crop itself.
It is a tall grass, rivalling the height of the finest cultivated oat crop, from some forms of which, and especially those with a lax panicle, it is at first not easily distinguished; however, a more careful examination and comparison with the so-calledAvena sativa(cultivated oat) enables us to make out the following differences:—
The experiments about to be detailed were performed with theAvena fatua.
In 1851, a quantity of this plant was noticed by the author on the farm of C. Lawrence, Esq., near Cirencester. It was mixed with a patch of mangel-wurzel which had been planted for seed; and from these specimens sufficient seeds were preserved wherewith to sow one of our experimental plots.
It should be noticed that the substratum was forest marble, and no doubt the seeds of the oat were brought with the manure by which the mangold patch was dressed.
In the spring of 1852 a plot of two and a half yards square was sown with seed which had been kept during the winter—a fact which should be carefully noted, as it forms a first and most important link in the chain of evidence, and constituting what we term a cultivative process, inasmuch as in wild growth the seeds are sown as soon as they become ripe.
The seeds of the first crop came up well, and on ripening, towards autumn, the plants were tall and robust; the grains presented a scarcely appreciable difference from the wild examples; if any, there may have been a slight tendency to an increased plumpness of grain.
The seeds of crop No. 1 were again collected and preserved throughout the winter, and sown in a patch of similar size, but in a different part of the garden, in the spring of 1853, repeating the process with the successive crops in 1854 and 1855, with slight alterations from year to year, though in some examples the following tendencies seemed from thefirst to be gaining strength in some few of the specimens:—
1st. A gradual decrease in the quantity of hairs on the pales.2nd. A more tumid grain, in which the pales were less coarse and the awn not so strong and rigid, and less black than in the wild example.3rd. A gradual increased development of kernel or flower.
The seeds of 1855 crop, without selection, were treated in the same manner during the winter, and were sown in the spring of 1856, the resulting crop in August of the same year presenting the following curious circumstances:—
1st.Avena fatua(typical wild oat), with large loose panicles of flowers,[10]thin hairy florets, with a bent awn twisted at the base. Five parts of crop.2nd.Avena fatua, var.sativa, with loose panicles of flowers, florets quite smooth, tumid, with or without straight awns, some few examples slightly hairy towards the base. This is the potato-oat type. Six parts of crop.3rd.Avena fatua, var.sativa—Panicles more compact, flowers inclining to one side, grains more tumid than 2nd, quite devoid of hairs, awn straight. These present the type of the white Tartarian oat. Twelve parts of crop. Fig. 2. Seeplate.
[10]Some examples of this plant, gathered at Framilode, in the Vale of Gloucester, in the past autumn, gave as many as 750 seeds to a root, from which its rate of increase as a weed may be imagined.
[10]Some examples of this plant, gathered at Framilode, in the Vale of Gloucester, in the past autumn, gave as many as 750 seeds to a root, from which its rate of increase as a weed may be imagined.
Having now procured a crop of separate types of oat from the same seed, we preserved them distinct, and this year carried on our experiments by cultivating a patch of each, whilst the plot of 1856 was left with self-sown seeds, in order that it should again become wild by degeneracy.
From these experiments, then, we may conclude that different types of crop oats are derived from theAvena fatua, or wild oat; but, besides this, they open out a subject for inquiry of great practical interest and importance, which may be clearly stated as follows:—
If by cultivation the wild oat assumes the cultivated form, then by degeneracy cultivated oats may become wild ones.
Those who know what a detestable weed is the wild oat wherever it occurs, and how difficult it is to eradicate,[11]will at once see the cogency of the question involved.
[11]The author once went with a rector of a parish in Gloucestershire to examine the glebe allotments of the poor people, when, catching sight of an apparent crop of oats, the landlord threatened to dispossess the tenant, “because he had carelessly left his crop without gathering.” However, the matter was explained when it was pointed out that the land was planted with wheat, which the oats had quite smothered.
[11]The author once went with a rector of a parish in Gloucestershire to examine the glebe allotments of the poor people, when, catching sight of an apparent crop of oats, the landlord threatened to dispossess the tenant, “because he had carelessly left his crop without gathering.” However, the matter was explained when it was pointed out that the land was planted with wheat, which the oats had quite smothered.
Farmers in some districts, and more especially on stiff clay soils, have ever objected to the cultivation of oats, as they had always maintained that they left behind a crop of weed oats. This, which was never a favourite idea with the botanist, who is generally too much inclined to species-making, seems now to have a basis of truth, for not only is it confirmed bythe experiments described, but observation of an independent kind points to the same truth.
On examining the produce of shed, or accidentally scattered oat seeds, the first crop will often present the wild tendency in a partial reversion to the hairy state, an elongation and thickening of the awn, and a lessening of the size of the kernel; and this more particularly on heavy soils. It was, indeed, an observation of this change in oats scattered on forest marble clay which induced us to try the experiments above detailed; and as the subsoil of our botanical garden is the same clay, we are, perhaps, indebted to this cause for arriving so soon at such signal results.
Again, it is known in farming that some clay lands will never produce heavy oats; a sample, however good, is sure to degenerate upon such soils. Hence, then, the foregoing experiments and observations lead to the following conclusions:—
1st. The wild oat is perhaps not a native of Britain, but derived through the degeneracy of the cereal crop; and hence its occurrence only as an agrarian.2nd. The cereal oat, on the contrary, is the result of the impress of cultivative processes upon the wild form, and as such liable to lapse into the wild state with greater or less celerity, according to the circumstances of soil and situation.
These conclusions are of practical value, as they show the direction in which experiments should be conducted in order to attain to varieties, it being a well-known fact that one variety is suitable for onesoil, and another for a different kind of land. And again, as some forms of plants would seem to have the tendency of wearing out by long cultivation, so we have the means of applying to the original source of their production, and thus of commencing a new generation.
They teach us, too, the necessity of avoiding the growth of the oat crop in some situations, and which in the case before us is not the result of the “pigheadedness” with which the farmer is often so thoughtlessly accused, but a conclusion founded in reason; and if we consider how robust is the growth of the wild oat, and that its support is secured by robbing the grain crop with which it occurs as a weed—the difficulty of separating it from the crop where it has gained a footing—and, above all, that its succession is secured by its seeds universally ripening a few days before that of the crop with which it is mixed, and the moment they are ripe they fall and become self-sown,[12]—we can see abundant reason for wholesome fear as to the introduction of cereal oats in districts liable to their degeneracy.
[12]The wild forms shed their seeds much more readily than the cultivated ones, and are, besides, earlier in ripening, and thus much of our wild seed had dropped before the other forms were fully ripe; and it much assists experiments in transmutation not to let the seeds with which they are to be carried on become dead ripe. This is another cultivative process.
[12]The wild forms shed their seeds much more readily than the cultivated ones, and are, besides, earlier in ripening, and thus much of our wild seed had dropped before the other forms were fully ripe; and it much assists experiments in transmutation not to let the seeds with which they are to be carried on become dead ripe. This is another cultivative process.
Wild oat spikeletSpikelet of the Wild Oat.[13]
Spikelet of the Wild Oat.[13]
[13]FromPopular Science Review, vol. i. p. 10.
[13]FromPopular Science Review, vol. i. p. 10.
The annexed enlargedfigureof a bunch of wild oat seeds will sufficiently illustrate the changes necessary to produce the cultivated form.
Under cultivation, which supposes theselection, saving up, and sowing in a preparedbed of our seed,the wild oat seed gradually becomes smooth externally, and its awn less coarse, while internally the grain becomes larger and heavier; so that while the seed of the wild oat would weigh about 15 lb. per bushel, that of a fine sample of white cultivated oat sown on our farm this year weighed as much as 48 lb. per bushel.
Now, the proof of this theory consists in the facts—
1st. That heavy oats degenerate by beingcultivatedin poor soil.
2nd. Bybeing let go wild, they sink still lower, and gradually assume the external hairs, stiff awns, and poor grain of the wild oat.
The cereal barley is found to offer three important forms, which can be best explained by the annexed diagramatic arrangement:—
The two-rowed barley has been namedHordeum distichum; and as we are inclined, with Professor Lindley, to the belief that this is the original from whence the other forms have sprung, we here quote the learned Professor’s remarks upon this and the probably allied forms:—
“It is probable,” he says, “that all kinds of barley grown by farmers are varieties of one species, of which, theH. distichumof Linnæus is the type. The spikelets of this genus always standing in threes, and the threes being placed back to back, it is evident that every ear of barley must consist of six rows of spikelets. If the middle spikelet of each set of threes is alone perfect, the side spikelets being abortive, we haveH. distichum, the common two-rowed barley, and its many varieties; if the two-tuberal of each set is perfect, and the central spikelet imperfect, as sometimes happens, then we have four-rowed barley; if, on the other hand, all the spikelets are perfect, we have six-rowed barley, orH. hexastichum;[177]but the cases of four-rowed barley have been merely accidental—they may be referred to the six-rowed form; and thus we have only two principal kinds of barley—namely,H. distichumandH. hexastichum.“1.H. distichum.—This is the only kind of barley that has been found apparently wild. We have now before us specimens gathered in Mesopotamia during Col. Chesney’s expedition to the Euphrates, with narrow ears, a little more than an inch long, exclusive of the awn, or four and a half inches awns included; and others from the ruins of Persepolis, with ears scarcely so large as starved rye. Both are straw-colour, but that from Mesopotamia has the glumes much more hairy than the other. The plant is also said to inhabit Tartary. The report that it grows wild in Sicily seems to have arisen from the MediterraneanÆgilops ovatahaving been mistaken for it. To this species belong all the varieties, from one to sixteen, formerly mentioned under Barley; as also does No. 20, fig. 34[14]—theH. zeocriton, sprat or battledore barley, an undoubted result of domestication, chiefly remarkable for the ears being so much broader at the base than the point as to produce a long ovate figure.“2.H. hexastichum.—We found no record of this having been found wild, and presume it and its numerous varieties to be domesticated forms ofH. distichum. The common bere, or winter barley, may be taken as the typical form to which Nos. 18, 21, and 22, and figs. 37 and 38[15]are evidently referable, varying in size, colour, and hairiness, more than in any other circumstance deserving botanical appreciation.“TheH. vulgareof Linnæus is a form with the grains in four rows, the naked-eared variety of which is again theH. cœlesteof some writers.“Both these forms of barley vary with naked seed, the pales losing their adhesion to the grain. But this difference is attended with no other peculiarity.“3. TheH. trifurcatum, also known under Dr. Royle’s name ofH. ægiceras, is a very remarkable naked-seeded species, with much the appearance of wheat. It is a tall or glaucous six-rowed sort, but the rows are not placed in lines with the same exactness as in the two former kinds, so that the ears are round like wheat. The pales[178]are apparently in a monstrous form, the ends being three-lobed, and curved back in the form of horns, which sometimes extend into awns. It has been introduced from the Himalaya Mountains within a few years, but its economical qualities remain to be determined.”[16]
“It is probable,” he says, “that all kinds of barley grown by farmers are varieties of one species, of which, theH. distichumof Linnæus is the type. The spikelets of this genus always standing in threes, and the threes being placed back to back, it is evident that every ear of barley must consist of six rows of spikelets. If the middle spikelet of each set of threes is alone perfect, the side spikelets being abortive, we haveH. distichum, the common two-rowed barley, and its many varieties; if the two-tuberal of each set is perfect, and the central spikelet imperfect, as sometimes happens, then we have four-rowed barley; if, on the other hand, all the spikelets are perfect, we have six-rowed barley, orH. hexastichum;[177]but the cases of four-rowed barley have been merely accidental—they may be referred to the six-rowed form; and thus we have only two principal kinds of barley—namely,H. distichumandH. hexastichum.
“1.H. distichum.—This is the only kind of barley that has been found apparently wild. We have now before us specimens gathered in Mesopotamia during Col. Chesney’s expedition to the Euphrates, with narrow ears, a little more than an inch long, exclusive of the awn, or four and a half inches awns included; and others from the ruins of Persepolis, with ears scarcely so large as starved rye. Both are straw-colour, but that from Mesopotamia has the glumes much more hairy than the other. The plant is also said to inhabit Tartary. The report that it grows wild in Sicily seems to have arisen from the MediterraneanÆgilops ovatahaving been mistaken for it. To this species belong all the varieties, from one to sixteen, formerly mentioned under Barley; as also does No. 20, fig. 34[14]—theH. zeocriton, sprat or battledore barley, an undoubted result of domestication, chiefly remarkable for the ears being so much broader at the base than the point as to produce a long ovate figure.
“2.H. hexastichum.—We found no record of this having been found wild, and presume it and its numerous varieties to be domesticated forms ofH. distichum. The common bere, or winter barley, may be taken as the typical form to which Nos. 18, 21, and 22, and figs. 37 and 38[15]are evidently referable, varying in size, colour, and hairiness, more than in any other circumstance deserving botanical appreciation.
“TheH. vulgareof Linnæus is a form with the grains in four rows, the naked-eared variety of which is again theH. cœlesteof some writers.
“Both these forms of barley vary with naked seed, the pales losing their adhesion to the grain. But this difference is attended with no other peculiarity.
“3. TheH. trifurcatum, also known under Dr. Royle’s name ofH. ægiceras, is a very remarkable naked-seeded species, with much the appearance of wheat. It is a tall or glaucous six-rowed sort, but the rows are not placed in lines with the same exactness as in the two former kinds, so that the ears are round like wheat. The pales[178]are apparently in a monstrous form, the ends being three-lobed, and curved back in the form of horns, which sometimes extend into awns. It has been introduced from the Himalaya Mountains within a few years, but its economical qualities remain to be determined.”[16]