Maria Gaasø
More ideas from Maria
Clean Water ALgae

A manual designed to help "water analysts and others who deal with the many problems and effects associated with the presence of algae in water supplies.

Ernst-Haeckel_5_defaultbody

a subclass or, according to another taxo-nomic system, an order of free-swimming marine coelenterates of the class Hydrozoa. The body, which ranges in length fr