46 THE EVOLUTION OF MAN. 



organic phenomena of life, of nutiifcion, reproduction, sensa- 

 tion, and movement. If wu tried to construct, a priori, tlie 

 simplest conceivable organism, we should always Le com- 

 pelled to fall Ijack upon such a Monera. 



Although in all real Monera the l:>ody consists merely 

 of such a small living piece of plasson, yet, among the 

 Moneraj which have been observed in the sea and in 

 fresh water, we have lieen able to distinguish seveiul dif- 

 ferent genera and species, varying in the mode in ^^'hic]l their 

 tiny bodies move and reproduce. In the ways in which 

 movement is accomplished very noticealile differences exist. 



Fig. 16.3. — A Moneron {Protaivceba) in the act of reprodnction : A, the 

 whole Moneron, which moves, like the ordinary Amoeba, by means of variable 

 i:)rocesseB ; B, a contraction ronnd its circnmference parts it into two halves ; 

 C, the two halves separate, and each now forms an independent individual 

 (much enlarged). 



In some Monera, especially in the Protamoeba (Fig. 1G3), 

 the formless body, during its movements, invariably de- 

 velops only a few, short, and blunt processes, which project 

 like fingers, slowly altering their form and size, liut never 

 branching. In other Monera, on the other hand {exj., 

 Protomyxa, Myxastrum), very numerous, long, fine, and 

 generally thread-like processes arise from the surface of 

 the moval'le liody, and these branch irregidarlj^ inter- 



