WA TER FLEAS. 



137 



ing. The two powers which move the human world, 

 love and hunger, seem to reign quite as predominantly 



Fig. 97. 



Fig. 98. 



Water flea (Daphnia pttlex) 

 male, enlarged to correspond- 

 ing proportion as Fig. 97. 



Water flea (Daphnia pulex) female, magnified 

 to show internal organs. The small figure en- 

 closed within a circle shows the natural size. 



among animalcules. It is not "live and let live," 

 however, which is their rule ; but " might is right ! " 



