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area to wheat. Professor Carleton calculates that by 1950 the 

 "improved farm area" will reach 760,000,000 acres, and that 

 there will also be a gain in the percentage of farm land devoted 

 to wheat, giving 76,000,000 acres of wheat land. In the last 

 forty years there has been a gain of 1.8 bushels to an acre; by 

 1950 a yield of 16.8 bushels per acre is predicted — a gain of 2.7 

 bushels per acre. The methods of increasing the acre yield: 

 (i) the introduction of better adapted varieties, (2) hybridization 

 and selection in existing varieties, and (3) better methods of 

 cultivation are discussed. Professor Carleton states that the 

 most important introduced wheats were those of the Fife (brought 

 from eastern Europe through Scotland and Canada into the 

 northern states of the plains) and from Crimea or Turkey 

 (brought from the Crimea and established in the middle states 

 of the plains). The combined output of these two types of 

 wheat now comprises nearly the entire wheat production of the 

 country. These wheats have not only extended the area to the 

 north and west but have increased the acre yield. Credit is given 

 the U. S. Department of Agriculture for much improvement 

 in existing varieties by selection and by hybridization. Yet, that 

 and the improvement due to progressive farming methods are 

 deemed but in their infancy. 



Recent study by K. F. Kellerman and J. R. Robinson, of the 

 Bureau of Plant Industry, shows that the presence of magnesium 

 carbonate (0.25 per cent, or over) is "positively inhibitive to 

 nitrifying action; i. e., toxic to the bacteria so important to the 

 nutrition of plants". Calcium carbonate is favorable up to 

 two per cent. Fairly pure calcium carbonate should therefore 

 be used in liming soils already containing magnesium. 



At the third International Botanical Congress held in Brussels 

 in May some new rules on nomenclature were formulated. Lin- 

 naeus's Species Plantarum, 1753, is to be retained as the starting 

 point for the myxomycetes, lichens, and liverworts; but more 

 recent authorities are to be used for fungi (1801, Persoon, and 

 1821-32, Fries); for algae (Linnaeus in part; 1848, Rolfs; 1886- 



