ng things exist to-day, and have existed in the past so far
as palaeontology can tell us, are consistent with the view that they are
all related by the community of descent which the accepted theory of
evolution demands, though as to the exact course of descent for any
particular group of animals there is often considerable diversity of
opinion. It is obvious that all this work has little or nothing to do with
the manner in which species are formed. Indeed, the effect of Darwin's
_Origin of Species_ was to divert attention from the way in which species
originate. At the time that it was put forward his explanation appeared so
satisfying that biologists accepted the notions of variation and heredity
there set forth and ceased to take any further interest in the work of the
hybridisers. Had Mendel's paper appeared a dozen years earlier it is
difficult to believe that it could have failed to attract the attention it
deserved. Coming as it did a few years after the publication of Darwin's
great work, it found men's minds set at rest on the problems that he raised
and their thoughts and energies directed to other matters. {13}

Nevertheless one interesting and noteworthy attempt to give greater
precision to the term heredity was made about this time. Francis Galton, a
cousin of Darwin, working upon data relating to the breeding of Basset
hounds, found that he could express on a definite statistical scheme the
proportion in which the different colours appeared in successive
generations. Every individual was conceived of as possessing a definite
heritage which might be expressed as unity. Of this, 1/2 was on the average
derived from the two parents (_i.e._ 1/4 from each parent), 1/4 from the
four grandparents, 1/8 from the eight great-grandparents, and so on. _The
Law of Ancestral Heredity_, as it was termed, expresses with fair accuracy
some of the statistical phenomena relating to the transmission of
characters in a mixed population. But the problem of the way in which
characters are distributed from gamete to zygote and from zygote to gamete
remained as before. Heredity is essentially a physiological problem, and
though statistics may be suggestive in the initiation of experiment, it is
upon the basis of experimental fact that progress must ultimately rest. For
this reason, in spite of its ingenuity and originality, Galton's theory and
the subsequent statistical work that has been founded upon it failed to
give us any deeper