THE CELL AS A MICROBE 55 



and work in single colonies which have no relation 

 to one another; but cells form and work in many 

 colonies, and these colonies all unite into one com- 

 munity and work together, like individuals, for a 

 still higher purpose. 



Along with this higher capacity for associative 

 work is also developed in the cell a higher and 

 more complex vital relation. In its primitive form 

 the microbe seems to have little or no vital rela- 

 tions with its fellows. At all events, the only tie 

 in this respect is between parent and child, and 

 this is wholly prenatal. At the moment of birth 

 the tie is broken. The child wanders away from 

 parent and lives an independent life, caring noth- 

 ing for parent, and parent caring nothing for 

 child. 



At a later stage in the evolution, when the col- 

 ony is formed, the vital relation seems to be a 

 little more pronounced. Especially is this the 

 case when the individuals of the colony are glued 

 together, all surrounded by a protecting mem- 

 brane, and act as a single individual. But even 

 here the relation is feeble. Separate one or more 

 individuals from the colony, and they are not 

 harmed by the separation, but under culture grow, 

 multiply and form a new colony; while the parent 

 colony is not harmed but mends itself and goes 

 on as before. 



Now, in many-celled life, whether vegetable or 

 animal, the evolution of the vital relation is taken 

 up exactly where it is left off by the microbe. 



