ANTHRAX GROUP 339 



Morphology and Staining. The Bacillus lactimorbi is a rod 

 somewhat smaller than the anthrax bacillus, usually single or in 

 pairs, occasionally in filaments. It is motile by means of 10 to 15 

 peritrichous flagella. Capsules have not been observed. Spores 

 are produced in the ends of the rods, and are slightly greater in 

 diameter than the rod itself. The young rods stain unevenly 

 with methylene-blue, and show very distinct metachromatic 

 granules. The organism is gram-positive. 



Isolation and Culture. Jordan and Harris isolated the organ- 

 ism directly upon agar plates from the intestinal contents bile, 





Fig. 140. Bacillus lactimorbi, showing rods and spores (X 1100) (Jordan 

 and Harris in " Journal of Infectious Diseases"). 



spleen, liver, and pericardial fluid. The agar colonies are small 

 and Streptococcus-like. The growth on agar slants is moderate 

 at first, later more luxuriant, but without distinct differential 

 characters. Gelatin stabs show incipient liquefaction in about 

 ten days. Bouillon is somewhat clouded, and a well-defined 

 pellicle forms. Milk is not coagulated. In litmus milk the reac- 

 tion is observed to become more alkaline, and there may be some 

 development of opalescence due to the great increase in alkalinity. 

 There is no growth upon potatoes. Blood-serum is not liquefied. 



Physiology. The optimum growth temperature is probably 

 about 37, although good development takes place at room-temper- 



