BUREAU OF ANIMAL INDUSTRY. 243 



been ^YO^ked out. Department Circular 272, givino; results in popular 

 form, has been issued, and a technical bulletin has been prepared. 



Two loco plants, Astragalus notoxys and Astragalus trootoni, in 

 addition to otliers previously investigated, were shown to be poison- 

 ous. 



Preliminary work was done toward determining which species of 

 lupine are poisonous and to what extent and which are harmless. A 

 detailed chemical study of several species is under way. 



The possibility of poisoning by greasewood {Sarcohatus vermicu- 

 latus) has been demonstrated experimentally, and it has been shown 

 that the poisoning is caused by the oxalates of sodium and potassium 

 in the plant. Some questions remain to be cleared up in regard to 

 losses under range conditions. 



Chemical investigations to identify and isolate the poisonous prin- 

 ciples of stock-poisoning plants have been continued. Alkaloids 

 have been isolated from some of the lupines. In an extended investi- 

 gation of white snakeroot {Eupatonum urticcefolium) enough in- 

 formation has been obtained to give a fairly good idea as to the 

 chemical relationships of the toxic principle. Experiments on sheep 

 with extracts of this plant leave no room for doubt as to the decided 

 toxicity of the plant. 



BRANCH LABORATORIES. 



The work of the branch pathological laboratory at Chicago con- 

 sisted largely of making diagnoses of pathological conditions en- 

 countered in meat inspection. 



In view of the large increase in the slaughter of cattle which liave 

 reacted to tuberculin and the failure to find visible lesions of tuber- 

 culosis at autopsy in many cases, an experiment on 12 cattle was 

 carried out to throw light on this condition. The results indicated 

 that cattle after exposure to tuberculous infection become sensitive 

 to tuberculin and react to tlie test before lesions of sufficient size to 

 be seen on autopsy have developed. 



In an experiment to test the possibility tliat some of the tuber- 

 culous lesions found in and beneath the skin of cattle might be caused 

 by tubercle bacilli of the avian type, 7 chiclvcns tested with avian 

 Tuberculin and found to be free from tuberculosis were allowed to 

 feed on tuberculous lesions of the skin in 113 cattle during a period 

 of five months, but autopsy showed that infection had not been trans- 

 mitted. 



The branch laboratory at Omaha, Nebr., received 921 specimen tis- 

 sues for diagnosis and study, of which 696 were from tuberculin re- 

 actors showing no lesions. The rc^naining specimens represented a 

 wide variety of diseases and conditions. 



The branch laboratory at Denver, Colo., received 783 specimens 

 for examination. Besides aiding the meat inspection, cooperation 

 was extended to the city and State health departments and to veteri- 

 narians and stockmen. 



BIOCHEMIC DIVISION. 



The work of the Biocliemic Division, under Dr. M. Dorset, chief, 

 consisted chiefly of laboratory research relative to meat products, 

 investigations concerning hog cholera, studies of dips, disinfectants, 

 and insecticides, and the preparation of tuberculin and mallein. 



