120 THE CYTOLOGY AND LIFE-HISTORY OF BACTERIA 



Resting 

 Stages 



Swarm 

 Vegetative 

 Reproduction 



THE LIFE-CYCLE IN EUBACTERIA AND MYXOBACTERIA 



be too keen to permit of the immediate success of a single transplant, of this 

 kind. New substrates are more frequently introduced to micro-organisms 

 already present, than vice versa, and are thus inoculated with a considerable 

 number of spores or resting cells, derived from the last period of growth in 

 the same area. 



In effect, therefore, the unit of growth and reproduction, in eubacteria 

 as in myxobacteria, is the swarm or bacterial culture. The culture grows and 

 ages, physically and physiologically, exactly Hke a multicellular organism, 

 and differs from one mainly in the lack of speciaHsation of its component 

 cells, hi myxobacteria some degree of speciahsation has been achieved in 

 the formation of the various parts of the fruiting body, but in eubacteria all 

 cells have an equal reproductive potential. 



The similarity between the cytology of the reproductive processes of the 

 two groups makes it apparent that their life-cycles are basically ahke, and this 

 similarity is increased by the existence o( the cytophagas which appear to 

 be intermediate between them in many respects ; resembhng eubacteria in 

 their saprophytic habit and absence o{ fruiting bodies, myxobacteria in the 

 large microcyst and the morphology of the bacterium. 



