BUREAU OF ANIMAL INDUSTRY. 119 



POULTRY DISEASES. 



An extensive outbreak of birdpox in a lot of 400 quail gave oppor- 

 tunity to investigate this disease, especially in the relationship be- 

 tween the disease in wild birds and in the domestic fowl. Transmis- 

 sion experiments showed that while fowls contracted the affection, 

 the lesions were not as severe as those following infection by chicken- 

 pox virus. 



Attempts to produce an active immunity against fowl cholera were 

 carried out on a large scale, a living, nonvirulent fowl-cholera or- 

 ganism being employed for the purpose. Treated fowls and small 

 experiment animals resisted high dilutions of a virulent strain of 

 the fowl-cholera bacillus when given by hypodermic injection, but 

 except in several instances failed to resist doses of from 1 to 0.01 

 c. c. of a 48-hour bouillon culture. However, it is doubtful if birds 

 are ever exposed to such large amounts of infectious material in nat- 

 ural outbreaks of fowl cholera. 



Work was continued on the development of a practical test for the 

 diagnosis of Bacillus pullorum infection in fowls. Results are en- 

 couraging, but the investigation has not progressed sufficiently to en- 

 able us definitely to determine the accuracy of the test for the detec- 

 tion of the disease in all its stages. Since the localization of this 

 bacillus in the ovary of laying hens is responsible, through the medium 

 of the egg, for the extensive outbreaks of the highly fatal bacillary 

 white diarrhea of baby chicks, it is of great importance that a sim- 

 ple, inexpensive test be developed for the purpose of detecting and 

 weeding out the infected fowls. 



INVESTIGATIONS OF PLANT POISONING OF STOCK. 



The work relating to the plant poisoning of stock was transferred 

 to the Bureau of Animal Industry from the Bureau of Plant Indus- 

 try at the beginning of the fiscal year. The experimental work con- 

 sists essentially in the collection of supposed poisonous plants and 

 feeding them experimentally to animals supposed to be susceptible 

 to injury. During the past year experiments were conducted upon 

 nine different plants. A brief synopsis follows: 



Zygadenus or death camas. — A bulletin has already been published 

 which covers the essential facts regarding this plant. Experiments 

 have been conducted recently with a view of determining more defi- 

 nitely the relative toxicity of the different species, as it has been 

 found that all are not equally poisonous. 



Lupine. — The work on lupine is also considered as largely com- 

 plete, so far as the general subject is concerned. However, as but 

 little chemical work has been done upon this plant, further feeding 

 experiments have been conducted in order to determine definitely 

 the relative toxicity of the different species, as it has seemed very 

 improbable that all are equally poisonous. 



Aconite. — Aconite grows in great abundance in all mountain ranges 

 in the West and is popularly supposed to be equally dangerous with 

 the larkspur. Work in the past years has shown that in all proba- 

 bility cattle are seldom if ever poisoned by aconite. This work, how- 

 ever, is by no means completed. Feeding experiments on this plant 

 have been carried on during the past year and some rather unex- 

 pected results have been obtained. 



