This also is unreasonable, and still more untenable, since it assumes that the same duct is used by the nutriment and the excretions; while if we assume that digestion is effected by any of the other internal parts, the objections already stated will apply: unless we were to assume that excrement is not formed from all nutriment, nor in all animals, any more than in plants, for we cannot find it in every one of the bodily parts, or even if we do, at least not in all animals.