CHAPTER VII. 

 MICROCOCCUS (Hallier, Cohn). 



BY the specific term micrococcus is understood a minute 

 spherical or slightly oval organism (spherobacterium, Cohn), 

 that like other bacteria divides by fission (schizomycetes), 

 and that does not possess any special organ, cilium or 

 flagellum, by using which it would be capable of moving 

 freely about. Micrococci, like other granules when suspended 

 in a fluid medium, show (Brownian) molecular movement. 

 Micrococci propagate always by simple division, never by 

 any other means, e.g. gemmation and spores. All assertions 

 to the contrary are based on incorrect observations. All 

 micrococci possess a delicate membrane of cellulose, and 

 owing to this resist the action of alkalies and acids. The 

 contents are homogeneous and highly refractive while active, 

 pale when inactive. They consist like those of other bacteria 

 of mycoprotein (Nencki). The size of micrococci varies 

 within considerable limits, say 0-0005 to o*2 millimetres, 

 or even a little more. Micrococci vary greatly as regards 

 both size and mode of growth. All multiply by slightly 

 elongating and then dividing by a transverse constriction 

 into two : a dumb-bell ; each of these again divides into two, 

 either transversely or in the same direction as before. The 



