Shows how the gradual changes in a pond affect living things from the end of winter to the beginning of summer. Includes extreme close-ups and photomicrography to show protozoa and other minute forms of life found in a pond.
1993
2014
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1978
1987
2021
2025
2022
1954
1952
2005
1996
1927
1930
2023
1976
1975