86 MORPHOLOGY AKD CULTURE OF MICROORGANISMS 



at right angles to their long axis (Fig. 65). There is, therefore, only 

 one arrangement or cell grouping possible, and that is end to end, so 

 that str?ptobaciUi are formed. When arranged in pairs, the designa- 

 tion is diplobacilli. The length of the chains appears to depend not 



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'S« I: 





EiG. 65. — Division forms of bacilli, a, Single; 6, pairs; c, in threads. f^After Novy.) 



only upon the cohesion of the bacilli but also upon the shape of the 

 end; those which have square ends frequently have very long chains, 

 while those with rounded ends have short chains or occur singly. 



Cell Aggregates among the Spirilla. — ^The same kind of 

 arrangement is maintained among the spirilla. 





Fig. 66. — Threads of Bad. anthracis. {After Migula.) 



ZooGLOEA. — Some of the bacteria secrete a mucilaginous substance 

 which causes the cohesion of the cells frequently in considerable number. 

 This aggregate of cells may assume some characteristic appearance and 



