BUREAU OF PLANT INDUSTRY. 277 



breeding work in California promises to develop valuable new strains. 

 Improved methods of handling and cultivating already worked out 

 are being applied by practical hop growers, and new points on prun- 

 ing, fertilizing, and otherwise treating the plants are being carefully 

 investigated. Laboratory studies of volatile oils, resins, acids, and 

 other important constituents of hops in their relation to yield, quality, 

 etc., are being carried on. Suggestions looking toward the judging 

 of hops on the basis of their properties and constituents rather than 

 on their supposed geographic origin have attracted wide attention 

 among growers and users and promise to bear fruit in a practical way, 

 since it is believed that the adoption of such standards will go far 

 toward removing certain sorts of discrimination which are at present 

 made against American hops. 



Tannin and dye-plant work. — The investigation of wild tannin 

 plants of the United States with reference to their availability and 

 value has been continued. Analyses of tannin extracts from a num- 

 ber of native plants have been made, and leather samples tanned with 

 extracts from this experimental material have been obtained. Tech- 

 nical difficulties, such as variations in the shade of leather tanned 

 from difl'erent samples of the same plant, have been encountered and 

 remain to be worked out. The experimental cultivation of several 

 of the more promising tannin crops has been undertaken. 



Tea-culture investigations. — The work in tea culture carried on 

 in cooperation with Dr. Charles U. Shepard, of Summerville, S. C, 

 has continued to give favorable results. The new season, although 

 somewhat discouraging from the standpoint of rainfall, has given a 

 satisfactory tea yield. From the present outlook' it seems likely that 

 the best record of the experiment will be equaled. The efforts of 

 Mr. George F. Mitchell to introduce machinery methods where hand- 

 work is now used have proved successful in the matter of pruning. 

 The pruning machine has been successfully used during the past 

 season to give both the flat and convex tj^pe of cut. The tea-picking 

 apparatus is now receiving attention and some small samples of 

 machine-picked tea have been obtained. 



poisonous-plant investigations. 



Loco-WEED INVESTIGATIONS. — Laboratory studies are being contin- 

 ued in the search for the active principle responsible for the char- 

 acteristic effects of loco poisoning. The problem is an exceedingly 

 difficult one and a continuance of the investigation is required. The 

 observations of European scientists as to the occurrence of an alkaloid 

 in the loco plant have been A'erified. Studies of this alkaloid, how- 

 ever, have not shown it to be very toxic. Evidence of toxic saponins 

 has been discovered in these plants and efforts are at present being, 

 directed toward their isolation. 



Larkspur poisoning. — Such species of larkspur as are available at 

 the feeding camp near Baldwin. Colo., have been investigated, and 

 antidotal treatment has been worked out and tested with promising 

 results. 



Cooperation with the Poorest Service. — A number of forests in 

 which much plant poisoning occurs have been visited and carefully 



