528 EXPERIMENT STATION KECOED. 



drometer was found very efficient in this respect, and tlie tolerance to salt of 

 a large number of plants was determined. 



As a result of his investigations the author concludes that the salinity of the 

 water, which can be determined by the hydrometer, is the determining factor 

 in the distribution of salt marsh plants, although the texture of the soil, its 

 aeration, and the lines of marsh drainage are influential factors. The author 

 further states that the method applied is also adapted to the study of alkali 

 soils, especially in the western States, and that the farmer can test the presence 

 or absence of salts and their relative amounts in the soil by this method. 



Minnesota plant studies. IV, Minnesota mushrooms, F. E. Clements 

 {Minneapolis, Minn.: Geol. and Nat. Hist. Surrcii, 1010, pp. 169, i)ls. 3, figs. 

 123). — This publication is designed for plant lovers and for classes in botany in 

 high school and college. It gives simple and concise descriptions of different 

 species of mushrooms occurring within the State. 



Plant introduction for the plant breeder, D. Fairchild (Z7. S. Dept. Agr. 

 Yearhoolc 1911, pp. J,tl-li22, i)ls. 6, fig. 1).—A popular account is given of the 

 work of the Office of Foreign Seed and Plant Introduction of the Bureau of 

 Plant Industry of this Department in securing species and varieties of plants 

 from various parts of the world to be used by plant breeders in their efforts to 

 obtain new combinations of characters that may prove of superior merit or 

 adapted to specinl environmental conditions. 



The present state of the mutation theory, L. Blaringhem (Bui. Soc. Bot. 

 France, 5S (1911), No. 8, pp. 6.iJf-652). — The author briefly reviews the recent 

 work of various investigators bearing upon the theory of mutation. In conclu- 

 sion it is stated that the theory has not been impaired but rather strengthened 

 by the more recent findings of these and related investigatious. 



CEnothera nanella, healthy and diseased, H. de Vries (Science, n. ser., 35 

 (1912), No. 906, pp. 753, 75'/). — Attention is called to the discovery of Zeijlstra 

 regarding the presence of a bacterium in the tissues of dwarf CE. nanella (E. S. 

 R., 27, p. 30). Zeijlstra, however, found that under favorable conditions the 

 side shoots of the dwarfs may become healthy and lose their abnormal charac- 

 ters. 



The author carried on some experiments with this dwarf type of ffinothera in 

 which plants were grown with a reduced amount of nitrogen and greater 

 quantities of phosphate of calcium. The resulting plants showed all transi- 

 tions between diseased and normal dwarfs, from which it is inferred that 

 Zeijlstra's discovery instead of diminishing the value of (E. nanella as a useful 

 mutant has shown means of cultivating it in a healthy condition. 



FIELD CEOPS. 



[Range improvement, plant introduction, and plant breeding], J. J. 

 Thornher, G. F. Freeman, and D. F. Jones (Arizona 8ta. Rpt. 1911, pp. 533- 

 5Ji6). — The conditions on the small and on the large range reserves during the 

 past year are discussed. The last 2 seasons have been generally unfavorable 

 to grazing interests. In this connection a report of progress is made on an 

 experiment in the cutting of fence posts at different seasons. 



In the introduction garden over 200 new plants were set out, and descriptions 

 are given of the behavior of Rhodes grass (Ghloris gayana), Japanese kudzu 

 vine (Pueraria thunhergeana), and tamarisks (Tamarix spp.). 



The work in plant breeding along agronomic and horticultural lines was con- 

 fined to alfalfa, dates, beans, and sweet corn. During the year 29 new pedigi-ee 

 strains of alfalfa were tested. The yield and quality of hay of 2 strains were 

 again well above the average. 



