BUREAU OF PLAKT INDUSTRY. 169 



losses of live stock in those States. Special attention was given to 

 the loco probleiTj, since the various species known under the general 

 name '• loco '' are among the first plants to appear on the ranges and 

 in the Southwest are responsible for more damage to live stock than 

 any other group of plants. In addition to the loco plants hitherto 

 recognized as harmful it has been found that a species which causes 

 serious losses of cattle in Arizona is the so-called " sheep loco '' 

 {Ash'agalus nothoxys). 



In addition to the toxic alkaloid of Dicentra cucidlarla, the dis- 

 covery of which was reported last year, another new toxic alkaloid 

 has been found in Dicentra canadensis. There is a marked difference 

 in the toxicity of these two plants, D. caiutdensis being about one- 

 sixth as toxic as D. cuciiJlaria., the species which has often caused 

 losses of cattle in the mountain pastures of Virginia. 



Further study has been made of Ornithogalum umhellatum, the 

 plant which had been reported as poisonous to sheep in eastern Mary- 

 land. From evidence collected in the field it now seems improbable 

 that this plant was the cause of the poisoning, as originally reported. 

 Investigation has shown that the plant contains a compound which 

 is very toxic when introduced into the circulatory system of small 

 animals, but is apparently harmless when administered by mouth. 



Considerable variation has been found in the hydrocyanic-acid 

 content of selected individual plants of Lotus corniculatus. Some 

 of the individual plants tested were free from hydrocyanic acid, but 

 among others the content of this acid ranged from 0.006 to 0.07 per 

 cent. If the propagation of acid-free strains of this species should 

 prove to be feasible, it will be possible to extend materially the use 

 of the plant as a forage crop. 



COTTON. 



ProhJem of utilizing superior varieties of cotton. — Experience 

 with cotton has shown that the utilization of superior varieties is a 

 fundamental problem, requiring careful study. On account of the 

 present organization or lack of organization in the cotton industry, 

 most of the seed is inferior, and there is no assurance of any general 

 utilization of good varieties. Methods of breeding and acclimatiza- 

 tion have been developed and demonstrated, but other requirements 

 must be met if a full utilization of superior varieties is to be secured. 

 The discovery and development of a series of superior varieties, in- 

 cluding the Lone Star, Trice, Columbia, Meade, Durango, and Acala, 

 make it possible to place the different regions of the Cotton Belt on 

 new planes of improved production, and all these varieties are being 

 grown as extensively as the available supplies of good seed will 

 permit; but the inadequacy of the present systems of providing 

 annual supplies of planting seed is also being recognized and methods 

 of improvement devised. Efforts are being made, therefore, to avoid 

 the general mixing of seed at the public gins and the crossing of the 

 different varieties in the fields, which undoubtedly are responsible for 

 the rapid and general deterioration of seed stocks that tend to keep 

 our producing industry on a low plane of efficiency'. 



One-vai'iety cotton gins. — Though the mixing of seed of different 

 varieties at public gins is a fact very familiar to cotton growers, 

 the nature, extent, and results of such mixing are not generally 



