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



dark central areas with hazy peripheries. Under the low power 

 they show dark opaque centers with wavy branching peripheries. 

 Deep colonies frequently show peculiar prickly margins. Gelatin 

 completely liquefied at the end of about two weeks and may show 

 a thick scum on the surface. 



Broth. Turbidity and a flocculent sediment in 24 to 48 hours 

 with a gradual production of a heavy scum which appears often 

 only after 4 days. In old cultures the precipitate is quite 

 heavy. 



Peptone. Turbidity and heavy flocculent sediment. Scum may 

 be thick and heavy or entirely lacking. 



Potato. Usually a rather scanty moist yellow or yellow-brown 

 growth. 



Milk. No change in reaction. Litmus begins to decolorize in 

 48 hours and by the end of two weeks is completely decolorized. 

 At the same time the proteins are digested and the resulting fluid 

 is a pale rather thin colorless solution. No coagulation. 



Blood serum. Thin cream-white non-spreading growth becom- 

 ing yellowish-brown in old cultures. No Hquefaction. 



Fermentation tubes. Glucose : thick scum, turbidity in bowl, arm 

 clear. Reaction alkaline. 



Saccharose : reactions the same. 



Lactose : reactions the same. 



Thermal death point. The spores survive steaming 30 minutes 

 but are destroyed by 45 minutes exposure. They may survive a 

 pressure of 16 pounds in the autoclave but are destroyed by 18 

 pounds pressm^e. ■ 



V Bacillus centrosporus nov. sp. 



This is a new species obtained but once, from the normal de- 

 jecta of a child from the Harriet Lane Home. 



Morphology. In 24 hour cultures on plain agar at 37°C. or 

 in 36 hour cultures at 22°C. long thin bacilli with pointed ends 

 fusiform or Clostridium in shape with slightly granular proto- 

 plasm (grassy), occurring usually as single cells measuring 0.375 

 to 0.5 by 3 to 4.5 microns in dimensions. The majority of the 



