It was the purpose of this study to (a) make a systematic survey of the algae of a fresh-water pond for one full year and, (b) to try to associate weekly and seasonal variations (periodicity) with certain ecological factors. A third objective was realized although was not originally planned and this was the data on fauna observed during the investigation. Factors selected for this investigation were chemical (N, P, K, Mg, and Ca, pH and 02 content), and physical (temperature, wind velocity and direction, and amount of light striking the surface). Of 293 species identified in this study, 188 are being reported as new for our studies of Virginia. The number of species represented in this study clearly indicates that this was a very productive pond. Even though the number of species representing the fauna were not recorded, the discussion of their presence would also indicate that they represented an array of forms from the protozoa to the metazoa.