224 
G. Udny Yule . 
complex process has taken place. The latter Mendel found to 
he the case; two races, ABC and abc being crossed, and the 
hybrids bred inter se, the resulting offspring exhibited not merely 
the parent forms but all the eight possible combinations of 
somatic characters— ABC, aBC, AbC, A Be, nbC, aBc, Abc, 
and abc, some being pure and some hybrid forms, as before. 
These re-combinations of characters and the approximate pro¬ 
portions in which they occurred Mendel held to indicate that 
each somatic character observed has some distinct and separable 
germinal representative—“ Anlage,” determinant or physiological 
unit, as we might term it—and that the formative divisions of 
the germ cells always take place in such a way that the finally 
formed gametes are homogeneous with respect to each character of 
a pair—no cell containing any pair of determinants like Aa or 
Bb —but otherwise at random. He experimented on one pair 
of characters in Pi sum, form of seed (round or angular) with 
cotyledon-colour (yellow or green), and on one triplet, seed-coat 
colour (grey-brown or white) in addition to the above, and the 
law held in both cases with reasonable accuracy. Mr. Bateson 
and Miss Saunders give in the Report particulars of a few ex¬ 
periments on pairs of characters, viz., colour of flower (violet 
or white) with character of fruit (smooth or prickly) in Datura, 
character of comb (rose or single) with extra toe in crosses of 
Leghorn with Dorking fowls, and colour of plumage with form 
of comb (pea or single) in crosses of Leghorns with Indian Game 
Fowls. The numerical proportions obtained by the experimenters 
in these cases diverge more or less (most notably in the second 
case) from those to be expected on Mendel’s hypothesis, but 
there is no denying the re-combinations of characters that have 
taken place; starting for instance with breeds of poultry exhibiting 
rose comb with extra toe and single comb without extra toe, 
respectively, two new breeds were obtained exhibiting single comb 
with extra toe and rose comb without. 
Mendel’s hypothesis is so ingenious and remarkable, and possibly 
of such far-reaching importance, that one can understand Mr. 
Bateson speaking of it as the “ essential part ” of his discovery, 
to the complete exclusion of the law of dominance and the various 
laws of numerical proportions which summarised the facts observed. 
These last two laws obviously enough do not hold in many cases. 
If they are excluded as not “essential,” the “top-hamper,” to use 
Mr. Bateson’s nautical metaphor applied to another matter, “ is cut 
