Method in the Study of Totemism

Is there any human institution which can be safely called "Totemism"? Is there any possibility of defining, or even describing Totemism? Is it legitimate—is it even possible, with due regard for "methodology" and logic—to seek for the "normal" form of Totemism, and to trace it through many Protean changes, produced by various causes, social and speculative? I think it possible to discern the main type of Totemism, and to account for divergences.