832 EXPERIMENT STATION RECORD. [Vol.48 



<l<;scrii)tions of the principal varieties cultivated in the oases of the Ahaggar 

 region, and discusses the adaptation of the wheat to the conditions peculiar to 

 Sahara. 



Wheat grade announcement, E. T. Mekedith (U. S. Dept. Agr., Bur. Mar- 

 kets Serv. and Regulatory Announcement 62 (1920), pp. 12, figs. S). — This in- 

 cludes the announcement of the Secretary of Agriculture that no change will 

 be made in the present standards for wheat, noted previously (E. S. R., 40, p. 

 39), and a discussion of proposed modilications in which the relation of the 

 test weight per bushel to the flour yield as determined by the North Dakota 

 Experiment Station and this Department, the relation between moisture con- 

 tent and value of wheat, and the moisture content of spring wheat crops in the 

 years 1911-1916 are illustrated graphically. 



Longevity of the seeds of cereals, clovers, and timothy, H. B. Sifton 

 (Amer. Jour. Bat., 7 {1920), No. 6, pp. 2^3-251, figs. 5).— The author reports 

 observations on annual germination tests made from 1903 to 1919, inclusive, 

 at the Seed Laboratory, Ottawa, Canada, of samples of spring wheat and 

 oats of the 1900-1902 crops, and clover and timothy of the 1902-3 crops. The 

 samples included all standard varieties of the time, and were collected in suc- 

 cessive years from the same farmers in representative parts of Canada The 

 author discusses the factors underlying the results and includes much data in 

 tabular and diagrammatic form. 



The investigations showed that during extended storage of an average 

 sample of wheat its depreciation could be divided into three more or less 

 distinct periods. During the first 10 or 11 years the weak grains gradually 

 died, and then followed a period of 3 to 4 years when the grains of average 

 vitality died very rapidly. A few seeds, very tenacious of life, were still left 

 and slowly lost their vitality during the final period of about 3 years. 



The longevity of oats proved much greater than that of wheat, possibly owing 

 to the protection of the hulls. In the majority of cases a slight rise in germi- 

 nation was noted during the first 4 or 5 years of storage. The longevity curve 

 differed from that of wheat in two respects, the first period being longer and 

 the drop in the second period not nearly so steep, as the oat kernels lived 

 longer and more variations were observed in their span of life. Forty-one per 

 cent of the 19-year-old kernels were still alive. 



Timothy seed began to depreciate in value at once, the strongest kernels 

 being comparatively short-lived. The three periods of depreciation were not 

 so sharply defined as in the case of hardier seeds. The germination began to 

 fall off rapidly after the seventh year when it was 84 per cent, further reduced 

 by the twelfth year to 11.5 per cent, and gradually decreased to the seventeenth 

 year when the seed was practically all dead. 



Both alsike and red clovers possessed a larger proportion of long-lived seeds 

 (over 15 years) than wheat, but from the standpoint of the practical seedsman 

 their longevity was not nearly so great. After 11 years on the average, wheat 

 still germinated over 85 per cent, while alsike or red clover of the same age 

 germinated less than 40 per cent. 



The Danish State seed testing station (Copenhagen: Danish State Seed 

 Testing Sta., 11920], pp. 16). — This pamphlet describes the methods and scope 

 of work of the State seed-testing station at Copenhagen, claimed to be now the 

 oldest in the world. 



Cocklebur, A. A. Hansen (U. S. Dept. Agr., Dept. Circ. 109 (1920), pp. 6, fig. 

 1). — The weed and its manner of growth are described, and its distribution, 

 harmful effects, and uses indicated. In outlining methods of eradication, the 

 author urges the prevention of seed production and the destruction of the seed 



