THE SPIROCH&TACEM 629 



infants. The organism is very generally distributed in 

 nature and can be very readily isolated from sewage by 

 appropriate methods. It is an anaerobic, spore-forming 

 organism, 0.8/JL in width, and 1.6 to 4.8/z in length. It is 

 actively motile and flagella have been demonstrated. 



In culture media containing carbohydrates this organism 

 produces gas in large quantities. Russell analyzed the gas 

 and found it to be composed principally of methane. Milk 

 and other sugar media in which the organism has been 

 grown have a distinct odor of butyric acid. 



When injected subcutaneously into guinea-pigs this 

 organism causes most marked alterations. There is intense 

 inflammation at the point of injection with edema and 

 necrosis and the surrounding tissues are filled with gas. 

 The bacteria are distributed throughout the body of the 

 animal and can be isolated in pure culture from the blood of 

 the heart. All the internal organs are intensely congested. 



THE SPIROCHJETACE-ffi. 



The spirochsetacese may be roughly defined as a family 

 of the unicellular non-nucleated, spiral organisms, of the 

 order spirochetales , ! which may or may not possess an undu- 

 lating membrane as an extension from a central filament 

 and which may multiply in some instances by transverse, 

 in others by longitudinal division. 



This is scarcely the place to discuss in detail the various 

 opinions that have been expressed since the tune of Ehren- 

 berg concerning the true nature of this group of micro- 



1 Preliminary Report, Committee on Classification, etc., Soc. Am. Bact., 

 Jour. Bacteriol., 1917, No. 5, vol. ii. Studies in Classification, etc., by 

 R. E. Buchanan, Jour. Bacteriol., 1918, No. 6, vol. iii. 



