Diatoms are brown microalgae that can be found in all freshwater and marine environments. They are an important link in the ecological cycle. In streams and rivers you often see stones covered with a brown layer that is formed by diatoms.

Sand can look beautiful under the microscope. Of course there are many different types of sand and so far I have only studied a few types with the microscope.

Stomata consist of specialised cells that mainly occur on the underside of leaves. They regulate the gas exchange between the plant and it’s environment, the plant is 'breathing' through them, as it were. Stomata are very recognizable by the two bean-shaped guard cells that regulate the size of the opening.