In Pursuit of the Gene

50 ¨ GALTON’S DISCIPLES
variation. In an application for a professorship at Oxford, he had proposed
studying domestic plants and animals, as had Darwin, and using them to
gain insight into the “modes of occurrence of [discontinuous] variations
and, if possible, of the laws which limit them.” 10 In 1891 he published a paper
on floral symmetry, in which for the first time he asserted his growing
conviction that Darwinian evolution by selection of small variations—
“Variations in degree which at any given moment are capable of being arranged
in a curve of Error,” 11 as he expressed it—could not account for evolution,
concluding, “It is difficult to suppose both that the process of Variation
has been a continuous one, and also that Natural Selection has been
the chief agent in building up things.” 12
As he had anticipated, Bateson was passed over for the Oxford professorship,
but nevertheless he set out in earnest to document the existence of
discontinuities in evolution. As his wife described it, “He ransacked museums,
libraries, and private collections; he attended every sort of ‘show,’
mixing freely with gardeners, shepherds and drovers, learning all they had
to teach him.” 13 The result was his massive study, Materials for the Study of Variation:
Treated with Especial Regard to Discontinuity in the Origin of Species, published in
1894. In it, Bateson gave more than 886 examples of what he believed to be
discontinuous evolution.
Always eager for his friend’s opinion, Bateson sent Weldon a copy of
the unpublished manuscript in the spring of 1894. For years the two men
had been attempting to crush one another in friendly battle over scientific
principles. 14 Having read only the introduction, Weldon wrote to warn
Bateson that he was ill disposed to the whole idea of discontinuity. “At
present I do not quite grasp what you mean by discontinuity, by regression,
and by oscillation about a position of organic stability,” implying that
Bateson did not properly understand the subtlety and care with which one
must apply these statistical ideas. For more than a dozen pages Weldon
preached to Bateson with the ardor of a new convert about the nature of
statistics and the dangers of misinterpreting data on the basis of a too small
sample. He described in detail his own computations with dice and provided
numerical data in order to show Bateson the “importance of examining
large numbers of individuals.” In order to determine whether an ex-