Text by Mike Samworth, images by Mike Morgan. Dec. '95. Updated
by the Micscape Editor Sept. '99. Note to readers: since this
article was posted in 1995, the Microscopy UK parent website has
uploaded an enormous range of resources on the microscopic
world. These include video clips, 3D images, high quality images
of protozoa, articles on pond life and many other topics. Click
on the resources offered on the site's main index to see them.
Or search for a particular topic in the on-line library. Links
at base. Paramecium is a small unicellular organism that is
plentiful in freshwater ponds. It swims, rotating slowly, and
often changing its direction. Under suitable conditions it may
reproduce by dividing two or three times a day and so large
numbers may build up. It belongs to the group of organisms
called Protozoa. Most of these are microscopic with over 80,000
different species identified. The cells of fossil protozoa are
often found in enormous numbers. They can help in tracing oil-
bearing rocks and sediment