The important conclusion is forced upon us by these experiments with a needle, that even in so typical and highly organised a creature as one of the higher or five-fingered, air-breathing vertebrates, the egg-cell does not require any material admixture from the sperm-cell in order that it may successfully germinate and develop, but only a disturbance of equilibrium, which can be administered as well by a needle's point as by a sperm-filament! Yet the whole process of sexual reproduction undoubtedly has, as its origin and explanation, the fusion in the first cell of the new generation from which all the rest will arise, of the material of two distinct individuals. Thus the qualities of the young are not a repetition of the qualities of one parent, nor are they a mere mixture of the qualities of both parents (for contradictory qualities cannot mix). They are a new grouping of qualities comprising some of the one parent and some of the other and hence a great opportunity for variation, for departure from either parent's exact "make-up," is afforded, and for the selection and survival of the new combination. It is, it would seem, only in exceptional cases and for limited periods that uni-sexual or fatherless reproduction can be advantageous to a species of plant or animal. Such cases are those in which abundant food, present for a limited season, renders the most rapid multiplication of individuals an advantage to the species. But after this exceptional abundance has come to an end, the more usual process of reproduction by fertilised eggs (also necessary and advantageous for the preservation of the race by "natural selection in the struggle for existence" of the new varieties so produced) is resumed until again the abundant food is present, as in the annual history of plant lice and the plants on which they feed. FOOTNOTES: [Footnote 7: "Science from an Easy Chair," Methuen & Co., 1910.] CHAPTER XIV PRIMITIVE BELIEFS ABOUT FATHERLESS PROGENY In the preceding chapter I related the curious and exceptional cases of "fatherless reproduction" by means of true egg-cells, those cells of special nature produced in the organs called "ovaries," present in all but the simplest animals and plants. These egg-cells are usually, with elaborate sureness and precise mechanism after liberation from the ovary, fertilised by (that is to say, fused with) the complemental reproductive cells--the sperm-filaments--produced by other individuals, the males.