The fiber composition of the semitendinosus muscle of the rabbit.

The semitendinosus muscle of the rabbit is composed of a homogeneous fiber population. Fiber typing was carried out by means of light and electron microscopy according to which this muscle exhibits structural features that are either characteristic for both "red" and "white" fibers, or that do not allow for any classification according to the A-, B-, C-fiber system. Hence the long-held assumption that the semitendinosus muscle of the rabbit represents a classical paradigm of a "red" muscle should be revised in light of the present results.