This extrusion or expulsion by each of the conjugating cells of half its constituent elements is certainly very strange.[15] And it seems strangely deliberate.[16] Various theories have been formed on the subject, but at present there is apparently no satisfactory conclusion as to what exactly takes place. Some think that in the one case certain male elements are expelled, and in the other case certain female elements; and anyhow it seems probable that a complementary action sets in, by which each prepares itself to supply a different class of elements from the other, thus rendering the conjunction more effectual. Plato has been already quoted with regard to male and female being only the two halves of a complete original being. He also says (in the speech of Socrates in the _Banquet_) that the mother of Love was Poverty, and that Love “possesses thus far his mother’s nature that he is ever the companion of Want.” And it would appear that in the most primitive grades of life the same is true, and that two cells combine or coalesce in order to mutually supply some want or deficiency. Anyhow, in the process just described two points stand out pretty clear: first, the exact quality of the number of chromosomes contributed by sperm-cell and germ-cell to the fertilized ovum—which seems to indicate that the descendant being has an equal heredity from each parent[17]—though of course it does not follow that both heredities become equally prominent or manifest in the descendant body; and secondly, that the same is true of all the cells in this new body—that they each contain the potentialities of the joint cell from which they sprang, and therefore the potentialities of both parents.