310 



MICROBIOLOGY 



Examinations of the intestines of different species of animals 

 show that there are no striking differences between B. coli 

 obtained from these different sources, and that usually the two 

 varieties exist in the same intestine. Moore and Wright 6 did 

 not obtain cultures of B. coli from the intestines of fowls that 

 would ferment saccharose. 



Morphology. Bacillus coli varies considerably in its mor- 

 phology, according to the sources and the culture media from 



Fig. 65. Drawing showing 

 resemblance in morphology of 

 bacteria belonging to different 

 species. 1, B. suipestifer; 2, 

 B. coli and 3, B. typhosus. 



which it is studied. The more usual form is that of short rods 

 with rounded ends, from 0.4 to 0.7 /* in diameter by 1 to 3 /x 

 in length; sometimes, especially where the culture media are 

 not suitable for their growth, the rods are so short as to be 

 almost spherical, resembling micrococci in appearance, and, 

 again, they are somewhat oval in form or are seen as threads 

 of 6 fji or more in length. The various forms may be associated 



6 Moore and Wright. American Medicine, Vol. VIII (1902) p. 

 504. 



