BOTANY. 951 



having been very destructive in southern Arizona. Preliminary spraying experi- 

 ments with Bordeaux mixture were begun to test the possibility of controlling this 



disease and will lie continued the ensuing year. 



Report of the division of economic botany, II. M. Hall (California Sta. /.'/>'■ 

 1904, /'/'• 76-83). — A report is given by the assistant botanist on the investigations in 

 economic botany carried on between July, 1903, and June, 1904. During this time 

 a large number of plants were determined tor different correspondents and opinions 

 given relative to their economic value. At the same time studies were continued on 

 weeds and poisonous plants. 



Botanical studies are being made of ornamental and economic plants, and it is 

 hoped to have all such represented in the economic herbarium. The additions to 

 the general herbarium are shown, ami brief reports given on the plants received for 

 identification. 



An experiment on the relation of soil physics to plant growth, B. E. Liv- 

 [NGSton and <;. H.Jensen (Bot. Gaz., 88 {inn',), No. /, pp. 67-71, figs. 3).— -In a 

 previous report (E. 8. R., 15, p. 751 ) one of the authors expressed the opinion that 

 the nature of vegetation covering any upland area would he determined by the 

 amount of water present in the surface layers of the soil. To test this hypothesis 

 cultures were made in which crushed quartz of 3 grades was placed in open-headed 

 barrels and various nutrient sails were added. Plants of the same species and fre- 

 quently from the same clumps were transplanted to the barrels after they had been 

 sunken level with the surface i if the ground. The only difference between the '.', cul- 

 tures is said to have been that of the different grades of sand, which was crushed 

 quartz of almost pure silica. 



The 3 cultures were exposed to the same external conditions of precipitation, 

 moisture, soil, etc., and were started at the same time. For a few days no difference 

 could he noticed in the growth of the plants, but gradually those in the finest sand 

 gained the ascendancy in the rate of growth. The figures presented were made from 

 photographs taken a month and a half after the beginning of the experiment and 

 show decided differences in the rate of growth. 



A table is given showing the height of the different plants in the 3 cultures, and 

 while the figures presented are quite significant, they are said to not fully express 

 the inequality of the characters of the plants. 



It is held that this experiment offers somewhat conclusive evidence in favor of the 

 above-mentioned hypothesis. 



The effect of saltwater on plants, R. Otto (Ztschr. Pflanzenkrank., 14 (1904), 

 No. 8, /'/'. 136-140). — An account is given of injury to various plants by watering 

 them with the waste water from a stream which carried considerable salt in solu- 

 tion. The reservoir from whence the water was taken was filled from a stream that 

 flowed near a coal mine, and during the process of mining a salt spring was devel- 

 oped which flowed into the reservoir. The concentration of the salt solution became 

 so great after a time as to seriously injure all plants, the injury being first indicated 

 by the appearance of red spots on the foliage, ultimately followed by the death of 

 the plants. 



Analyses of dead plants and soils from pots in which they were grown showed the 

 presence in the air-dried soil of 0.193 percent of sodium chlorid. The ash of the 

 plants was also determined, and while sound plants had 25.92 per cent ash, the ash 

 of specimens killed by the saline water was 41.74 per cent of dry substance. 



The salt water limits of wild rice, C. S. Scofield (U. S. Dipt. Ayr., Bureau of 

 Plant Industry Bui. 7?, pt. 2, pp. 8). — The author records the results of an inquiry 

 into the degree of salinity which wild rice will withstand. This information was 

 sought to determine the practicability of planting wild rice in various localities. 

 The method of testing the salt content of the water was that used by the Bureau of 

 Soils for testing strengths of solution. 



