HIGHER PLANTS 



Occurrence. — Frequent in quiet water containing much 

 organic matter. Blooms July-August. United States south- 

 ward to Virginia and Texas and in scattered areas westward 

 to Arizona and Lower California. 



Animal associates. — These are mainly protozoans, nema- 

 todes, rotifers, minute insect larvae, and crustaceans. If a 

 plant with translucent empty bladders is put into an aquarium 

 well supplied with entomostracans (p. i6i), its bladders will 

 soon become darkened by their loads of captured animals. 



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