THIS MONTH'S WINNERS:

No winners for the summer, 2002 unknown!

Life in a glass house! - the diatom - Isthmia nervosa

Diatoms are single-celled algae. Two main types of diatoms are distinguished on the basis of their symmetry, the centric diatoms, and the pinnate diatoms. Isthmia nervosa is an unusual centric diatom, with a secondary bilateral symmetry.