It is now universally recognised that man uses for economic purposes not more than one tenth of the land of our planet. If we turn to the vegetable kingdom we shall see that only a little more than one per cent of flowering plants is under cultivation, not to mention the huge vegetative resources of oceans, seas, lakes and other reservoirs ; these riches are practically not utilised. Meanwhile, the vegetable kingdom conceals enormous potential possibilities for developing the productive forces of society, to improve the well-being of the people . Two principal ways of introducing new plants into cultivation are known . One way of transferring the most valuable botanical species from nature to cultivation is by introduction . The other is by utilisation of several characteristics and traits of wild plants for the creation of new botanical species . The method of remote hybridisation by which plants of various species, genera and families are crossed, has only just been applied for these purposes . Hybridisation of cultivated plants with wild ones is of particular interest for selection and also from the point of view of general biology . There are many wild species, still unused by man, that are noted for their extensive ecological plasticity, stability and other valuable properties, considerably surpassing in this respect many cultivated plants. This is explained by the fact that wild plants have acquired in the course of centuries certain biological properties and characters which are necessary for survival in their struggle for existence. Though cultivated plants have descended from wild plants man has been changing them for thousands of years to satisfy his own needs, frequently to the detriment of the requirements of the plant itself. This regularity, typical of biology as a whole, persuaded us of the possibility of fundamental transformation of the existing varieties of cereals by crossing them with wild plants couch-grass, wild rye, etc ; the principal idea of this work is to create hybrid varieties and forms possessing better properties and qualities and, hence, meeting the requirements of agricultural production . Naturally, we first of all turned to various species and varieties of cultivated wheat, which is of particular interest in the agriculture of the Soviet Union and many other countries . Remote hybridisation of cultivated cereals with wild plants of the same family was carried out with great difficulties . In our work we met with a very serious difficulty biological incompatibility and special methods based on the detailed investigation of the formative process from the point of view of physiology, cytology, biochemistry and genetics were