326 



BACTERIOLOGY. 



gether by gelatinous substance. Later they become 

 larger, globular or ovoid in shape, and hollow, con- 

 taining watery fluid in their interior. The families 

 reach a diameter of 660 /x, in which the cocci form 

 simply a peripheral layer. The hollow families or 

 vesicles are often perforated, presenting a delicate 

 reticulated appearance, which finally may become 

 broken up into irregular structures. The red colour- 



FIG. 127. SEVERAL PHASE-FORMS OF BEGGIATOA ROSEO-PERSICINA. 

 [After Warming.] 



ing matter can be distinguished from other red 

 pigments, and it is designated by the name bacterio- 

 purpurin. It is quite distinct from the pigment 

 produced by Bacterium ptodigiosum, being peach- 

 blossom red, and insoluble in water, alcohol, etc. 

 Examined spectroscopically it shows a strong ab- 



