Get an onion and peel off a thin layer of live tissue, not the dried part. Mount it on a slide, and you should be able to distinguish cells and material flowing between/around them.

There is enough stuff living in pond/lake/stream/river water to keep you busy for a very long time. If you live near the ocean, then you have even more to examine.

Insects provide some pretty amazing viewing opportunities. If you're lucky, you might even find some ectoparasites living on them.

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John Karlsson
Hope Valley, RI

Don't count your chickens until they have burned their bridges behind them.