504 C. A. LAUBACH, J. L. RICE AND W. W. FORD 



Motility. No motility has ever been observed, even in very 

 young cultures. 



Staining properties. Gram-positive. 



Spore formation. When first isolated this species formed 

 spores in 24 hours. After long artificial cultivation spores are 

 formed only after 4 to 5 days growth on both plain and glucose 

 agar. They are usually subterminal but may be central. The 

 rods swell appreciably before sporulation, sometimes in the cen- 

 ter and sometimes at the ends. The free spores are oval and 

 measure 0.625 to 0.75 by 0.875 to 1 micron. They often remain 

 fastened to each other in long chains. Frequently a bit of proto- 

 plasm remains attached to the spore which then resembles a ten- 

 nis racket with its handle. 



Agar slant. In early growth (18 hours) this species slightly 

 resembles Bacillus mycoides. The line of inoculation shows a dis- 

 tinct ridge from which shoot out fine interlacing filaments. These 

 adhere closely to and grow into the agar. Considerable puck- 

 ering of these interlacing filaments causes a roughened leathery 

 appearance on the surface. The early growth is moist and 

 slightly glistening but these properties are soon lost. The edges 

 of the growth are serrated, with little or no tendency to spread. 

 A brownish color is found in old cultures throughout the entire 

 medium. 



Agar slant. Profuse growth along the line of inoculation and 

 out into the medium. This has the appearance of an inverted 

 fir tree. 



Agar colonies. The colony is very characteristic. It first ap- 

 pears like a small colony of Bacillus mycoides, but within 24 

 hours the filaments seem to swell and produce a somewhat cor- 

 rugated surface with a very definite, elevated and yellow-brown 

 center. The entire colony adheres closely to the agar and gradu- 

 ally grows into it. 



Glucose litmus agar slant. The growth is similar to that on 

 plain agar but is very scanty. A definite and permanent acidity 

 is produced. 



Glucose litmus agar colonies. Colonies in this medium are 

 considerably smaller than those on plain agar and have the same 

 general appearance. 



