hell just
sufficiently to set it going--going on its course of division and
development. The only other case of "artificially-induced
parthenogenesis" at present recorded is that of the common frog, due
to M. Bataillon. There are questions of great interest still to be
made out as the result of his discovery. Can the fatherless brood be
reared to maturity and again made to yield a fatherless generation?
What is the precise structure of the nuclei of the cells which
originate from the nucleus of the egg-cell only, and not from a
nucleus formed by the fusion of that with a sperm-cell nucleus? These
and similar questions are the motive of further careful study now in
progress.

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 th