Fifteen of the best grains were selected, and in 1890 three of the resulting plants proved to be a wheat of the Square-head type and one quite sterile. The others retained the elongated, narrow, brownish-red ears, the flowering glumes again opening wide for some days. This last is a characteristic of rye, but not of wheat. A long series of natural hybrids of wheat, barley, and oats are also described and discussed by Rimpau, as well as artificial crosses--some very remarkable--of barleys, but they must be passed over here. Peas rarely become hybridised naturally. According to Darwin, H. Müller, and Focke, the flowers are little visited by insects in our countries, though the mechanism points to their adaptation for pollination by large bees. Rimpau confirms Darwin, H. Müller, and Ogle as to the self-fertilisation of our cultivated peas. Nevertheless, as is well known, marked varieties have been obtained by artificial crossing by Gärtner, Knight, Laxton, and others, especially in this country. At the same time experiments show that while it is very easy to obtain artificial hybrids of such plants, and there is no fear of natural inter-crossing, the forms are remarkably unstable as yet. Similarly unsatisfactory results were obtained with beet. As experiments are still going on, however, we may expect to hear more about these and other results. It is probable, from recent experiments by De Vries, Correns, and others, that a remarkable regularity, expressed by Mendel in the form of a law, obtains in the variations which result from hybridising. In considering these illustrative cases, it is necessary to thoroughly apprehend that two procedures are involved. In the first place we have the cross-pollination leading to the formation of the hybrid plant by cross-fertilisation. But experience shows that this would lead to very uncertain results if the plant-breeder did not supplement them by the second and extremely important process of rigid selection--_i.e._ by choosing the best of the progeny and breeding from them apart from the parent-forms, and gradually intensifying, as it were, the variations in certain directions which have been started by the crossing. It is by selection, careful culture, and repeated selection that so much has been done in obtaining the innumerable new varieties of roses, sweet-peas, orchids, orchard fruits, cereals, grapes, strawberries, melons, tomatoes, early potatoes, etc., brought forward by numerous breeders of plants in all countries, as will readily be understood if reference be made to the work of Hays and Webber in America; Saunders in Canada; Garton, Sutton, Veitch, Bateson, and others in this country.