Desmids are a type of green algae, usually single-celled, and known for being extremely symmetrical and nifty to look at. In this video, you can watch a desmid divide and grow into two new individuals. A desmid's symmetry comes from the fact that it's really made up of two identical parts joined by a central connection, which also houses the nucleus. What you're watching is that nucleus splitting in half and each half growing a new symmetrical side.
Via John Hutchinson