90 a EXPERIMENT STATION. [Jan. 



2. Study of Bacterium Pullorum Infection. 



During the year 1916 the project outlined in connection with 

 the studies on bacillary white diarrhoea has been conducted 

 along lines already established. The object of the work has 

 been to improve methods in diagnosis, to explain reasons for 

 symptoms in certain avian diseases at present but little under- 

 stood, and to aid in formulating methods in prevention and 

 control. 



The problem by nature of the biological phases of the work 

 is divided into three distinct parts, which are stated in the 

 following three headings: — 



(1) Specificity of B. pullorum antibodies, with special refer- 

 ence to the agglutinins. 



(2) Toxins elaborated by B. pullorum and their relation to 

 specific conditions in adult birds. 



(3) Investigations concerning the production of antibodies, 

 with special reference to potency and rate of production. 



(1) The work concerning the specificity of Bacterium pul- 

 lorum agglutinins has been continued since 1915, and tests and 

 procedures carried along concerning the use of 27 strains of this 

 organism isolated from birds in this State. Recently more than 

 10 new strains have been added to this list. The data obtained 

 and that being accumulated will have to do with testing thor- 

 oughly the agglutinins elaborated by animals and birds against 

 B. pullorum, with cultures particularly of the B. coli, B. typhi, 

 B. dysenterce group. By the end of the academic year 1917 it 

 is hoped that this phase of the Bacterium pullorum problem 

 will be ready for publication. At the present time 21 adult 

 birds are immunized against B. pullorum, and are producing 

 definite agglutinins. Fourteen rabbits also are used for these 

 studies, having been immunized and hyperimmunized during 

 the past year. 



(2) The problem concerning the production of toxin by B. 

 pullorum has engaged most of the time at my disposal for ex- 

 periment station work during the past ten months. This is 

 proving a most complicated and detailed matter for study, 

 and has involved almost endless detail concerning the matter 

 of obtaining a uniform toxin. Up to the present time a toxin 



