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 one soil, 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. The annexed enlarged figure of a bunch of wild oat seeds will sufficiently illustrate the changes necessary to produce the cultivated form. Under cultivation, which supposes the _selection, saving up, and sowing in a prepared_ bed 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 being _cultivated_ in poor soil.