7<5 THE OCEAN WORLD. 



It is believed that they are chiefly multiplied by parting with a 

 portion of their body substance, which is enabled to take on an 

 independent existence, and thus form a new individual. This is 

 what naturalists term generation by division i.e., fission. The 

 absence of a nutritive and reproductive system in the Amoeba, and 

 the want of stability in their forms, explain how nearly impossible 

 it is to characterise as species the numerous individuals to be met 

 with living in fresh or salt water. 



We shall be able to form some idea of the appearance of these 



Fig. io. Amoeba princeps (Ehrenberg\ 

 magnified 100 times. 



Fig. ii. Various forms of Amoeba diffluen? 

 (Muller), magnified. 



beings, rendered mysterious by their very simplicity, by throwing a 

 glance upon the two accompanying figures (Figs, io and n), bor- 

 rowed from the Atlas of Dujardin's " Les Infusoires," which we 

 shall have occasion to quote more than once. 



We have said that the Amcebiz change their form every few 

 moments under the very eyes of the observer. Fig. io represents 

 some of the changes of form through which they pass when examined 

 under the microscope. 



Dujardin points out very clearly the identity of structure between 

 organisms like Amoeba and such forms as Difflugia and Arcella. 

 All these creatures are without a trace of mouth or true digestive 



