The obvious answer to this is, that no one has ever supposed “gemmules” to be merely “_molecules_,” in the chemical sense of this word; nor has any one ever imagined that they are “_devoured_” by the germ-cells into which they pass. Of course, if this were the case—i.e., if gemmules serve merely as _food_ to the germ-cells—they would become disintegrated down even to their chemically molecular structure, and there would be an end of them as organized “carriers of heredity.” In the second place, it is asked:— How can such a process [i.e. the passage of gemmules into growing germ-cells] be conceivable, when the colony becomes more complex, when the number of somatic cells becomes so large that they surround the reproductive cells with many layers, and when at the same time, by an increasing division of labour, a great number of different tissues and cells are produced, all of which must originate _de novo_ from a single reproductive cell? Here, again, the obvious answer is, that no one has ever propounded such a statement. Far from supposing that “all the different cells and tissues of a complex organism must originate _de novo_ from a _single_ reproductive cell,” the theory of pangenesis supposes the very contrary—viz., that somatic changes in the past history of the phyla have _not_ thus originated in _any_ reproductive cell. The idea of somatic changes originating in reproductive cells belongs to the theory of _germ-plasm_; but even this theory does not suppose all the great number of different cells and tissues which compose a complex organism to have ever originated _de novo_ from a _single_ reproductive cell. The difficulty touching germ-cells becoming isolated, or buried, by the phylogenetic increase of somatic cells, is enforced in the immediately succeeding sentences, thus:— Each of these various elements [somatic cells] must, _ex hypothesi_, give up certain molecules to the reproductive cells; hence those which are in immediate contact with the latter would obviously possess an advantage over those which are more remote. If, then, any somatic cell must send the same number of molecules to each reproductive cell[70], we are compelled to suspend all known physical and physiological conceptions, and must make the entirely gratuitous assumption of an affinity on the part of the molecules for the reproductive cells. Even if we admit the existence of this affinity, its origin and means of control remain perfectly unintelligible if we suppose that it has arisen from differentiation of the complete colony. An unknown controlling force must be added to this mysterious arrangement, in order to marshal the molecules which enter the reproductive cell in such a manner that their arrangement corresponds with the order in which they must emerge as cells at a later period.