Thus we arrive in this way also at our earlier assumption that an inactive accessory-idioplasm is given to all, or at least to many cell-generations. Only among plants must this necessarily be complete germ-plasm, and among the lower plant-forms, as in _Caulerpa_ among the Algæ, in _Marchantia_ among Liverworts, it must be assumed to be present in nearly all the cells, according to the experiments in regeneration made by Reinke and Vöchting. But in multicellular animals which develop from two different germinal layers equipped with a different complex of determinants budding arises from a combination of at least two different kinds of cells, and we must only ascribe to each of these its own peculiar determinant-complex as regeneration-idioplasm. Higher plants show us that well-marked power of budding is not necessarily associated with a high regenerative capacity, the histologically specialized cells among them will contain no inactive germ-plasm, because they do not need it. But in animals the power of budding is probably always combined with high regenerative capacity, as is shown by the Polyps and Medusoids above all, and in a different way by the Ctenophores, which exhibit no budding and at the same time a very slight regenerative capacity, although they possess an organization scarcely higher than that of the Hydromedusæ. In the Ctenophores each of the first segmentation-cells, when artificially separated, yields only a half-embryo, and we may conclude from this that it contains no complete germ-plasm in an inactive state, or at least very little, and certainly not a sufficient quantity to make it readily regenerative. Undoubtedly, however, the regenerative capacity occurs apart from the capacity for budding, yet this in no way contradicts the theory. As we have seen, a high regenerative capacity is to be found among many animals which occur only as 'persons' and not as colonies or stocks, but only in those which are readily liable to injury, and only in the manner conditioned by their injury. In the higher Metazoa the regenerative power becomes more and more limited, and in the Mammals it sinks to a mere closing up of wounds.