546 



BACTERIOLOGY. 



FIG. 89. 



the sides of the rod. It forms spores that are usually 

 located in or near the middle of the cells, causing fre- 

 quently a swelling at the points at which they are 

 located and giving to the cell a more 

 or less oval, spindle, or lozenge shape. 

 (Fig. 88, B.) 



It is an obligate anaerobe, growing 

 on all the ordinary media, but not with 

 access of oxygen. It grows well in 

 an atmosphere of hydrogen. It causes 

 liquefaction of gelatin. 



In tubes containing about 20 to 30 c.c. 

 of gelatin that has been liquefied, inocu- 

 lated with a small amount of the culture, 

 and then rapidly solidified in ice- water, 

 growth appears in the form of isolated 

 colonies at or near the bottom of the 

 tube in from two to three days at 

 20 'C. These colonies, when of from 

 0.5 to 1 mm. in diameter, appear as 

 spheres filled with clear liquid, and 

 are difficult, for this reason, to detect. 

 (Fig. 89.) As they gradually increase 

 in size the contents of the spheres be- 

 come cloudy and marked by fine radi- 

 ating stripes, easily to be detected with 

 the aid of a small hand-lens. In deep 

 of malignant stab-cultures in agar-agar and in gela- 

 thf Tuiture. CeP (After tin development occurs only along the 

 FRANKEL and PFEIF- track of puncture, at a distance below 

 the surface. Growth is frequently ac- 

 companied by the production of gas-bubbles. 



It causes rapid liquefaction of blood-serum, with pro- 



Colonies of the l>a- 



