THE Welsh Plant Breeding Station, Aberystwyth, has just issued a bulletin entitled “The Temporary Ley”, price 7s. 6d. It is divided into four sections. The first compares the results obtained with station-bred and commercial grasses when used in simple mixtures. Although in the first year the commercial seeds gave the best yields, distinct advantages were shown by the station-bred varieties in the third year. Relative aggressiveness of the different species in a mixture is also an important point; timothy, for example, failing to become established when sown in conjunction with cocksfoot or perennial rye grass. Section 2 deals with the yield and persistency of different strains of grass and clover. Mixtures containing indigenous species gave both higher yields and better response to phosphatic manuring than those in which such species were in the minority or lacking. Pasture management and its effect on the sward is the subject of the third section. Swards differing widely in botanical composition were subjected to various systems of management, and it was found that the importance of a-species is determined by the individual reaction of the plant to the type of management, as well as its ability to withstand competition from other components of the sward under those conditions. The final section consists of an article by Sir R. George Stapledon, director of the Station, on the establishment and maintenance of.temporary leys. This will perhaps be of particular value to the agriculturist as it deals largely with the practical aspect of the question.—Final emphasis is laid on the fact that success depends on the combination of a well thought-out seeds mixture with good management.