FIELD CROPS, 81 



the author states that when dried these support for a short period (one-half 

 hour) temperatures above 100° C, and in some cases much higher. Some 

 suggestions as to the nature of these bodies are also offered. 



Excretion of toxic substances by roots, D. Prianichnikov {Rev. G6n. Bot., 

 25 his (1914), pp. 563-582, figs. 11). — ^Thls is mainly a discussion of the work 

 done by Periturin (E. S. R., 30, p. 420), the results of which agree in part 

 with those of American investigators named. 



Alterations in the forms of antagonism curves, W. J. V. Osterhout 

 (Jahrh. Wiss. Bot. [Pringsheim}, 54 {1914), No. 4, pp. 645-650, fig. i).— The 

 author, reporting an extension of work previouslj^ noted (E. S. R., 26, p. 823; 

 29, p. 027), shows by tables and curves how the antagonism between given 

 percentages of sodium chlorid and calcium chlorid may vary from time to 

 time in the course of a given experiment. This is held to be due to progressive 

 alterations in the permeability toward each salt of the living material em- 

 ployed, which in this case consisted of portions of Laminaria saccharina. It 

 is thought that these two salts act in different ways to influence permeability. 



The influence of X-rays on vegetation, E. Mi£ge and H. Coupfi {Compt. 

 Rend. Acad. 8ci. [Paris], 159 {1914), No. 4, pp. 338-340, pi. i).— Reporting ex- 

 periments with seedlings of Raphanus sativus and Lepidium sativum subjected 

 for about 38 days after planting to strong and frequent applications of X-rays, 

 the author claims that this preliminary study shows that these rays exert a 

 favorable influence upon the foliage, but more upon the underground portions 

 of these plants. The effect increases with the frequency and strength of the 

 application (even within limits dangerous to animal tissues), and the rays 

 affect the morphology and structure of these plants when grown under their 

 influence. 



FIELD CROPS. 



Plant breeding, G. F. Freeman and J. C. T. Uppiof {Arizona 8ta. Rpt. 1914, 

 pp. 343-348). — In variety tests reported with alfalfa it is noted that Peruvian 

 alfalfa has demonstrated its excellence for the region. In physiological studies 

 as to the nature of drought resistance, the results suggest a distinct relation 

 between the transpiration rate and the number of stomata on a given leaf 

 surface. 



It is noted that the sweet corn breeding experiments have resulted in pro- 

 ducing a variety that is hardy and drought and heat resistant from a few 

 grains originally found among the native corn grown by the Papago Indians. 



Cultural work with tepary beans and variety tests with wheats are also 

 reported. 



[Field experiments], A. M. McOmie (Arizona Sta. Rpt. 1914, PP- 330-333, 

 334-337). — Cultural tests being carried on at Phoenix and at the dry farms 

 at Sulphur Spring Valley, Prescott, and Snowflake with wheat, oats, rye, Indian 

 beans, millet, Sudan grass, corn, sugar beets, sugar cane, sorghums, potatoes, 

 legumes for cover and forage crops, millets, flax, and teosinte, and breeding 

 work with alfalfa are briefly reported. 



[Field-crop trials], J. M. Scott (Florida Sta. Rpt. 1914, pp. XXII-XXIX). — 

 This gives results of cultural trials of Sudan grass, teff, Wakulla bean, Yoko- 

 hama bean, Alachua bean, Florida velvet bean, soy beans, cowpeas, sweet pota- 

 toes, Chinese velvet bean, and kudzu bean. 



Sudan grass yields ranged from 1,245 to 4,960 lbs. of cured hay per acre 

 in 1913. " The sowings made in March produced only one cutting during the 

 year, while the later [April and May] sowings gave two cuttings." 



