Diatoms are beautiful single celled organisms. They make a glass house of silica consisting of two valves that fit into each other like a little pill box. The colour of the living tissue is yellow-brown instead of the green we know of other creatures that use light as a source for energy. The cells of diatoms are ideal subjects for study under the microscope. They show complex patterns of punctures and often have all kinds of ornaments.
Diatoms are one of the most abundant plants on the planet.
At the end of the winter, early spring, they bloom in freshwater. If you like to study them, try to scrape the brown growth of water plants or wooden poles. For the floating species a special fine mesh plankton net is very useful. In fresh water most diatoms are of the pennate type. In marine waters the variety of body shapes is much wider.