192 



STATE BOARD OF AGRICULTURE 



Numbers 4, 5, 6, and 7. Collected by Dr. Fitch, University of Minue 

 sota. Abortion history not given. 



Number 8. Collected by Dr. L. L. Lewis, Oklahoma A. and M. College, 

 from a cow wliich aborted a six months fetus ; natural infection. 



Number 9. Collected by Dr. Hallman near Traverse City, Michigan 

 from a cow two weeks after a'bortion ; natural infection. 



Number 10. Same source as number U; collected one week after 

 abortion. 



Number 11. Collected from four-year-old cow in Experiment Station 

 herd one month after abortion ; natural infection. 



Number 12. Collected by Dr. Connaway, University of Missouri, from 

 eight-year-old cow ; aborted fifth calf ; natural infection. 



Numljer 13. Same source as number 12 ; from four-year-old cow ; 

 aborted second calf; natural infection. 



Number 11, Same source as numiber 12 ; from eleven-year-old cow ; 

 aborted first, second and fifth calves; natural infection. 



Number 15. Same source; from three-year-old cow; aborted first 

 calf; natural infection. 



PATHOGENICITY OF BACTERIUM ABORTUS (bANG). 



' TABLE I 

 Showing History of Strains of Bact. Abortus Employed in the Comparative Studies 



growing 



Agglutination Test. The several antigens were prepared by 

 each strain of Bact. ahortus on liver agar (pH G.6) in Kolle flasks for 

 forty-eight hours, removing the growths with physiological salt solution 

 plus O.i") per cent phenol, filtering through sterile gauze to remove 

 clumi)s, mechanically shaking for four hours and finally standardizing to 

 a tui-'bidity of three by the McFarland nephelometer. In the tests, two 

 cubic centimeters of the antigen were placed in each of four small test 

 tubes and serum added in the following quantities : 0.05, 0.025, 0.01 



