The food Chain length is a continuous Variable that provides a measure of the passage of engery and an index of Ecological Structure that increases in value counting progressively through the linkages in a Linear fashion from the Lowest to the Hightest Trophic (feeding) Levels. Food chains are often used in Ecological Modeling (such as a three species food chain). They are simply abstracts of real food webs, but complex in their dynamics and mathematical implications. Ecologists have formulated and tested hypotheses regarding the nature of ecological patterns associated with food length, such as increasing length increasing with Ecosystem Size, reduction of energy at each successive level, or the proposition that long food chains are unstable.