FOUND ATIONAL AGES 9 



plication and the holding together of successive generations, 

 led to the formation of cell colonies or confederations. The 

 foundation of co-operation was thus laid. But although the 

 principle of union was in evidence, there is no reason to 

 suppose that any cells, excepting as regards free individual 

 locomotion, underwent any important change. Each cell 

 probably continued self-sufficing and carried on life much as 

 before. Loose confederations of this character are still in 

 existence (e.g. Monobia confluens). 



Monobia confluens, after A. Schneider. 

 (Highly magnified.) 



In course of time some of the colonies no doubt underwent 

 various changes of form, and some of them came to present a 

 ball-shaped appearance. But whatever their outward aspect 

 they must all have had to face the population question. 

 Cells were multiplying fast, and difficulties must have arisen 

 from want of organisation among the more or less independent 

 units. Resort, no doubt, was made to various expedients. 

 In the case of some colonies the problem was doubtless solved 

 by secession of cells from the union and the founding of new 

 colonies. If this had been the only way open, further progress 

 in life would have been indefinitely postponed, if not actually 

 imperilled. In the case of some of the ball-shaped colonies, 

 however, it may be assumed that the cells continued to hold 

 together ; and the power to vary was put to higher tests. 



