Abstract
The observation that more kinds of predators than prey comprise natural communities is more likely an artifact of systematic variation in the kinds of organisms that biologists distinguish at different trophic levels than a fact of nature. The opposite expectation is derived from a dynamic theory of community development. Observations should be gathered from which the numbers of trophic resources at different levels in natural communities can be determined. Vandermeer''s (1972) grain matrix should prove particularly useful.