WHEAT: ITS ORIGIN AND ACCLIMATIZATION.
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 a derivative plant 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 derived from experiment: this we now have, and upon it we quote the following from Mr. Bentham, in the Cyclopaedia 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, named Ægilops. 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 between Ægilops ovata and common wheat, he has practically proved their botanical identity; for, from the seeds of the Ægilops first 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 the Journal of the Agricultural Society, which led us to institute independent inquiries, to which end, having purchased some seeds of Ægilops 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 year after 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. 3 represents a spikelet of the type of Ægilops 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.
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 between Ægilops and 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 from Ægilops.
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 easy to 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.