156 RELATIONSHIPS OF THE COCCACE^ 



these points, the action of the streptococci on carbohy- 

 drates, which has proved of such great diagnostic value, 

 was first worked out by Dr. Mervyn H. Gordon of the 

 Medical Office of the English Local Government Board. 



Page (1899), eight years ago, made a quantitative study 

 of the acid produced by twenty-one different streptococci 

 in dextrose, lactose, and saccharose. All produced acid; 

 and Dr. Page concluded that the organisms could not be 

 separated by a quantitative study of fermentative power. 

 His tabulated results are of interest, however, as showing 

 several of the types worked out later by Gordon. Some 

 study of fermentative power has also been made more 

 recently in connection with the comparative studies on 

 the diplococci. Thus Ruediger (1906, b), in a study of the 

 streptococci from normal and scarlatinal throats, found 

 two types, one fermenting mannite and the other failing to 

 do so, as well as a group of organisms intermediate between 

 the streptococci and the diplococci. 



The comparative study of fermentative power on a 

 large scale we owe, however, to the striking investigations 

 of Gordon. His first studies along this line (Gordon, 

 1904) were made in the attempt to develop a test for 

 mouth bacteria, to be used in estimating air pollution. 

 He found that the most abundant organisms in the normal 

 mouth were cocci, and that the most ubiquitous of all were 

 the streptococci. The streptococci found in the mouth 

 showed the usual characters of Sir. pyo genes, varying in 

 the length of chains (Str. longus, Str. medius, and Str. 



