MICROCOCCUS TETRAGENUS CONCENTRICUS 257 



round islets appear, which when inoculation has been exten- 

 sive coalesce with one another, and by confluence of several 



Concentrically stratified 

 superficial growth 



Concentric stratification in a fis- 

 sure in the gelatine 



Deep portion of the needle-track 



PIG. 92. THBffST-OULTURE IN GELATINH OP MlCROCOCCCS 

 TETRAGENUS CONCENTRICUS. 



a larger roundish compound colony is formed, resembling a 

 holoblastic ovum in process of segmentation. Thrust-cul- 



s 



