NON-PATHOGENIC BACILLI. 693 



bacillus. The gases which are developed in cultures containing sugar have 

 a disagreeable odor like that of cheese and onions ; cultures in blood serum 

 give off a putrefactive odor. Not pathogenic for mice. 



409. BACILLUS SPINOSUS (Liideritz). 



Obtained from garden earth by inoculations into mice and guinea-pigs. 



Morphology. Bacilli with round ends, straight or curved, about 0.6 n 

 thick and of various lengths usually from 3 to 8 // ; may grow out into long, 

 segmented, flexible filaments. Spores are formed in the single rods only 

 and are long- oval in form ; they are located toward one or the other ex- 

 tremity of the rod, which is from 1 to 1.2 fi broad at the point where they are 

 developed, and has more strongly rounded or pointed ends than those not 

 containing spores. 



Biological Characters. An anaerobic, liquefying, motile bacillus. 

 Grows in the usual culture media, with the addition of two per cent of grape 

 sugar, at the room temperature, in the absence of oxygen. In gelatin tube 

 cultures, at the end of twodays at 20 C., colonies 

 are formed in the deepest portion of the gelatin 

 to within 3 or 3.5 centimetres of the surface; these 

 are irregular in form and the size of a poppy- or 

 hemp-seed ; they contain liquefied gelatin, and as 

 they increase in size the gray, shining contents 

 are seen to contain a radiating, whitish growth ; 

 this is most marked in the deep-lying colonies, in 

 which the radiating growth extends to the non- 

 liquefied gelatin around the colony; later the 

 colonies become confluent and the liquefaction 

 slowly extends upward. In agar tubes opaque 

 colonies are developed which may attain a dia- 

 meter of four millimetres ; under the microscope 

 they are seen to be made up of numerous inter- FIG. 240.-Bacillus spinosus; 

 laced filaments which in old colonies are only colony in nutrient agar, one 

 seen in the marginal zone ; or they may be com- day old. x 60. (Luderitz.) 

 posed of thick, knotty masses. Blood serum is 



liquefied by this bacillus. Gas is formed in all of the cultures, and in those 

 containing sugar it has an odor which is compared to a mixture of Swiss 

 cheese and fermented raspberry juice. Not pathogenic for mice or guinea- 

 pigs. 



410. BACILLUS ANAEROBICUS LIQUEFACIENS (Sternberg). 



Obtained in anaerobic cultures from the contents of the intestine of a 

 yellow-fever cadaver. 



Morphology. Slender bacilli, about 0.6 /* in diameter and three to five 

 times as long as broad; often in pairs: grows out into long filaments. 



Biological Characters. An anaerobic, liquefying, non-motile bacillus. 

 Forms spores. Grows in the usual culture media at the room temperature, 

 when oxygen is excluded. In gelatin roll tubes (Esmarch's) filled with 

 hydrogen, granular, white colonies are developed, around which the gelatin 

 is liquefied. In a long stick culture in nutrient agar it grows along the 

 line of puncture nearly to the surface. Pathogenic power not tested. 



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