854 



BACILLUS 



Potefo.— Abundant, mealy, greyish-brown, growth of viscous consistency ; surface 



granular. 

 Resistance. — Spores are said to withstand 15 lbs. steam pressure for 1 hour. Killed by 



20 lbs. in half an hour. 



Fig. 189. — B. mycoides. 

 Surface growth of rhizoid type on agar, 3 days, 30° C. (fths natural size.) 



Metabolism. — Aerobe ; facultative anaerobe. Opt. temp. 30° C. ; limits 10-40° C. Pig- 

 ment none. Some strains secrete a lysin capable of dissolving certain bacteria. 



Hcemolysis.— None on horse blood agar plates. 



Nutritional. — Grows fairly well on ordinary media ; growth not improved by blood, 

 serum, or glucose, but augmented by nitrates. 



1 

 V 



f y/ 



^ 



x 



Fig. 190. — B. mycoides. 



Flu. I',)l. IJ. mycoides. 



From an agar slope culture, 2 days, 30° C. Central part of a surface colony on agar, 3 

 (X 1000). days, 30° C, showing rhizoid structure (X 8). 



