BACTERIA, NOT CLASSIFIED. 721 



quickly extends over the entire surface. Does not produce an acid reaction 

 in milk. 



460. BACILLUS INUNCTUS (Pohl). 



Obtained from swamp water. 



Morphology. Bacilli 3.5 n long and 0.8 to 0.9 ju broad. 



Biological Characters. An aerobic and facultative anaerobic, liquefy- 

 ing, motile bacillus. Spore formation not observed. Upon gelatin plates 

 forms oval or round colonies with a smooth margin and oily, shining ap- 

 pearance. In gelatin stick cultures grows along the line of puncture, and 

 below the growth has a radiating appearance; upon the surface a thick, 

 white, shining layer is quickly formed ; later liquefaction commences and 

 progresses slowly. Upon the surface of agar white, cloud-like masses are 

 formed along the streak. Upon potato a white, slimy mass is formed which 

 soon covers the entire surface. In milk an acid reaction is produced by the 

 growth of this bacillus, but no coagulation occurs. In Pasteur's solution con- 

 taining cane sugar or starch an abundant development of alcohol occurs. 



461. BACILLUS FLAVESCENS (Pohl). 



Obtained from swamp water (1892). 



Morphology. Bacilli 2.1 to 2.2 /* long and 0.8 /* broad. 



Biological Characters. An aerobic, non-liquefying, chromogenic, 

 slightly motile bacillus. Spore formation not determined. Forms a yellow 

 pigment. Upon gelatin plates, at the end of four days, colonies are visible ; 

 these are yellow, granular, and attain the size of a pin's head. In gelatin 

 stick cultures it grows along the line of puncture, and slowly extends over 

 the entire surface. Upon the surface of agar small, solitary, yellow colo- 

 nies are developed along the track of the needle. Upon potato development 

 is somewhat more rapid, and at the end of four days the entire surface is 

 covered with a slimy, yellow layer. Gelatin colored blue with litmus is de- 

 colorized without the previous change of color to red. In milk an acid reac- 

 tion is produced without coagulation. 



462. BACILLUS BUTYRICUS OF BOTKIN. 



Obtained by Botkin. in anaerobic cultures from milk, from hydrant wa- 

 ter, well water, garden earth, and dust. 



Morphology. In agar and gelatin cultures containing one and one-half 

 per cent of grape sugar the bacilli are 0.5 ju long and 1 to 3 n in diameter, 

 with round ends ; they are often united in pairs or in chains of three ; in 

 liquid media they are not so thick, and often attain a length of 10 ju. or more, 

 without segmentation ; long chains may also be observed. The spores are 

 located in the centre of the rods, or occasionally at one extremity ; they vary 

 greatly in their dimensions; the diameter is usually about 1 > and the 

 length 2 to 3 //. In old cultures various involution forms are seen. 



Stains with the usual aniline colors. 



Biological Characters. An anaerobic, liquefying, slightly motile ba- 

 cillus. Forms large oval spores, which have a high resisting power for 

 heat. To obtain pure cultures Botkin subjects milk containing this bacillus 

 to the boiling temperature in the steam 'sterilizer for half an hour. The 

 spores resist this temperature, and the flask containing the milk is hermeti- 

 cally sealed and placed in an incubating oven at 37 C. At the end of twelve 

 hours, as a rule, fermentation commences; the casein is coagulated and col- 

 lects, together with the fat, at the upper part of the flask, while a clear, yel- 

 lowish serum is seen below ; there is an abundant development of gas. The 

 most favorable temperature for growth is 37 to 38 C., but development 

 may occur at temperatures ranging from 18 to 42 C. ; at 18 development 

 is very slow and usually no gas is formed. In culture media containing 



