828 EXPERIMENT STATION RECORD. [Vol.43 



around the scutellum, plumule, primary root, and root sheath. Severe freezing 

 of immature or moist corn causes the embryo to change from a normally light 

 or creamy color to a dark or yellowish-brown color, and this change is usually 

 accompanied by a loss of vitality. The appearance of the embryo, therefore, 

 is said to be a fairly safe guide in judging the germlnative power of seed corn 

 which has been subject to freezing injury. 



So far as they were able to detect, the authors found no injury of cell walls 

 or other cytological effect of freezing or ice formation. They consider from the 

 evidence at hand that freezing produces a physical or chemical change, aside 

 from the withdrawal of water, in the protoplasmic and nuclear material of the 

 cell so that life no longer exists. 



The vitality of corn containing from 15 to 20 per cent of moisture is not in- 

 jured by ordinary autumn freezing, and coi-n with from 10 to 14 per cent of 

 moisture will withstand the most severe winter temperatures without injury 

 to its germinative power. The kernels on an ear of corn are said to vary in 

 moisture content, which may explain partial germination of an ear of corn 

 after exposure to freezing temperatures. 



The variations in freezing weather, together with the great seasonal varia- 

 tions in time of corn maturity, are said to make freezing inevitable in occasional 

 years. Under Nebraska conditions the best types of corn should ripen two or 

 three weeks before the mean date of the first killing frost. Where varieties 

 ripen too late, their maturity may be hastened by field selection of seed and by 

 selection of drier and more mature ears later in the season. Crib selection of 

 seed corn may be practiced as a last resort. In years when corn matures well, 

 it is said to be a good practice to select sufficient seed for two years' planting. 

 The viability of seed corn should be ascertained before planting time, either by 

 a germination test or by observing the color of the germ. 



Considerable attention has been given to the relation between the yields of 

 corn and seed corn injury due to freezing, and from a study of the average 

 yield of corn for the past 28 years it is believed that a low yield does not neces- 

 sarily follow years of severe seed injury. 



Cotton culture in the Belgian Kongo, R. Mees {La Culture du Coton au 

 Congo Beige. Brussels: Govt., 1919, pp. 74, pis. 17). — This report comprises de- 

 scriptions of the cotton-producing regions, transportation facilities, the various 

 tribes of natives and their state of advancement, and discusses the conditions 

 deemed necessary to the rapid development of cotton culture in the region. 



Cotton in British West Africa, N. M. Penzek {London: Fed. Brit. Indus. 

 Intel. Dept., 1920, pp. 5S, pi. 1, fig. 1; abs. in Bui. Imp. Inst. [London], 17 {1919), 

 No. 4, pp. 609, 610). — This volume outlines the history and development of cotton 

 culture in West Africa, describing in some detail the status of the industry, 

 Including notes on transportation, cultural practices, crop pests, and varieties, 

 in Nigeria, Gold Coast, Sierra Leone, Gambia, Togoland, Cameroons, and the 

 Lake Chad district. The author" discusses the future of cotton growing in the 

 region, and presents tabulated statistics on the exports of cotton from the 

 various countries mentioned. A special introduction by Viscount Milner is 

 included, and a bibliography of cotton from 1881 to 1920, embracing 241 titles, 

 iB appended. 



Native fiber plants, G. Sellergken {K. Landtbr. Akad. Handl. och TidsTcr., 59 

 (1920), No. 1, pp. 54-63, figs. 5). — Historical notes on the use of native fiber 

 plants in Sweden are presented, and descriptions of Phragmites communis, 

 Scirpus maritimus and related species, and of different species of pines as 

 sources of fiber and pulp are given. 



Fibers from India, Africa, and the West Indies. — Flax, jute, and hemp 

 substitutes {Bui. Imp. Inst. [London], 17 {1919), No. 4, pp. 455-485).— Thin re- 



