92 RELATIONSHIPS OF THE COCCACE^ 



istics of the group as a whole. Classification, however, 

 must be phylogenetic rather than logical; and there is no 

 course but to include such aberrant forms in the group to 

 which they are on the whole related. 



The genus Ascococcus is a somewhat problematical 

 one since so little work, and almost no comparative work, 

 has been done upon the single peculiar type which it 

 includes. The properties of this genus are more fully 

 discussed in Chapter VI; but it seems most likely, in 

 the light of present knowledge, that these slime-forming 

 cocci of the sugar refineries are sufficiently peculiar to 

 warrant generic rank. They are apparently more closely 

 related to the diplococci and streptococci than to any 

 other groups. Their cell grouping, in chains made up of 

 paired units, their tendency to capsulation, and their high 

 fermentative power, all ally them with these two genera. 

 They may therefore be tentatively included under the 

 Paracoccaceae, in spite of their saprophytic habit. Until 

 comparative study shall rectify or expand the characteri- 

 zation, we have denned the genus as follows: 



Genus II. Ascococcus (Cohn) Winslow and Rogers. 

 Saprophytic, growing vigorously in saccharine solutions. 

 Cells in pairs, or in chains of paired elements. In presence 

 of certain carbo-hydrates large, lobed gelatinous masses of 

 zooglea formed. Fermentative powers high, acid being pro- 

 duced in dextrose, lactose, and saccharose. 



The third genus of the Paracoccaceae is the well-marked 

 group of the streptococci. These organisms are commonly 



