STUDIES ON FOWL CHOLERA 



287 



injection the rabbit showed definite symptoms of intoxication and 

 died in about six hours. 



The tests reported in the previous pages were sufficient to 

 demonstrate a total lack of toxicity in the culture or filtrates of 

 B. avisepticus (strain 48) employed, but to show the presence of a 

 strong toxic substance in the filtrate of forty-eight-hour cultures 

 of the organism used by Dr. Bull. The contrasts may be sum- 

 marized as follows: 



May perhaps become lethal after several passages through rabbits. 



In view of these discrepancies, it seemed desirable to examine 

 culturally the strain employed by Dr. Bull. It was therefore 

 submitted to the usual cultural and biochemical tests; and in 

 addition was tested for its agglutinative reactions with a number 

 of immune sera, including those of B. avisepticus and Bad. 

 gallinarum (fowl typhoid). These tests will now be described. 



Morphological, cultural arid biochemical features of Dr. Bull's 

 strain. Slides prepared from twenty-four-hour chicken agar 

 cultures and stained with gentian violet revealed a short plump 

 rod, having an average size of 0.7 by 0.45/x. a maximum size of 

 1.2 by 0.5 iJL, and a minimum size of 0.4 by 0.3 fj,. The ends of 

 the rods were rounded and many of the shorter rods resembled 

 cocci. Pairs of rods were common; chains of three seldom seen; 

 filaments occasionally. Peripheral staining was observed. 



