Algae of the Spirogyra genus make stringy, gelatinus heaps, like green coloured cotton wool floating in water. They only live in sweet water and can easily be found in slow moving water courses, puddles and ponds. As can be seen in the photograph taken through the microscope the chloroplasts (subcell structures containing chlorophyll) are like spiralling ribbons. (foto M. Dalle Vedove)

     Panel II Detailed and synthetic illustrations, using a systematic criterion, of the principal groups into which these organisms are divided (blue algae, green algae, brown algae and red algae).
     The principal macro/microscopic, distinguishing features of each group are described and some notes are added on the ecology.
     The panel also has a series of photographs showing what a colony of algae can look like to the naked eye and of some common algae as seen through a microscope.