306 J. S. LAWRENCE AND W. W. FORD 



or slightly granular rods measuring 0.75 to 1.5 by 3 to 6 microns 

 on plain agar in young cultures (8 to 24 hours), and 1 to 1.75 by 

 3 to 6 on glucose agar. Long forms measuring 12 to 25 microns 

 are seen on plain and on glucose agar. Shadow forms with 

 faintly staining protoplasm, like those seen in Bacillus megatherium 

 are common as well as the peculiar refractile globular bodies. 

 (Figures 38, 39, 40, 41 and 42.) 



Motility. Active progressive and rotatory motility in young 

 cultures. 



Staining reactions. Gram-positive. 



Spore formation. Spores are formed abundantly in 24 hours 

 on plain and on glucose agar. The spores are oval to rectangular, 

 of about the same width as the rods from which they spring 

 and frequently form long chains. The free spores may retain 

 tags of protoplasm but soon lose them and then show great vari- 

 ations in size and shape. They may be nearly round, oval, 

 rectangular and reniform and measure 0.75 to 1 by 1.5 to 2 microns. 



Agar slant. Thick, moist, abundant mealy growth at first 

 slightly pinkish by reflected hght, then becoming bright lemon 

 yeKow. Agar slightly discolored. 



Agar stab. Slight growth along line of inoculation with heaped 

 up yellowish growth on surface. 



Agar colonies. Surface colonies thick, white or yellow, highly 

 refractive. Under low power dark, granular with entire or 

 myceleoid edges. Deep colonies punctiform. Under low power 

 irregular, with irregular edges showing myceleoid, rooty or fuzzy 

 edges. 



Litmus glucose agar. Luxuriant, thick, heaped-up growth at 

 first yellow then assuming an orange and then a dark-brown color. 

 Reaction of medium first acid then alkaline. It eventually 

 becomes smoky-brown. 



Litmus glucose agar colonies. Surface colonies round, regular 

 and thick or thin and spreading. Under low power granular 

 with entire edges. Deep colonies punctiform. Under low 

 power granular, irregular, with fuzzy edges. Reaction of medium 

 acid at first then alkaline. 



