excepting in the quality of the grain
they all kept true: Colonel Le Couteur possessed upwards of 150, and
Philippar 322 varieties.[548] As wheat is an annual, we thus see how
strictly many trifling differences in character are inherited through
many generations. Colonel Le Couteur insists strongly on this same
fact: in his persevering and successful attempts to raise new varieties
by selection, he began by choosing the best ears, but soon found that
the grains in the same ear differed so that he was compelled to select
them separately; and each grain generally transmitted its own
character. The great amount of variability in the plants of the same
variety is another interesting point, which would never have been
detected except by an eye long practised to the work; thus Colonel Le
Couteur relates[549] that in a field of his own wheat, which he
considered at least as pure as that of any of his neighbours, Professor
La Gasca found twenty-three sorts; and Professor Henslow has observed
similar facts. Besides such individual variations, forms sufficiently
well marked to be valued and to become widely cultivated {315}
sometimes suddenly appear: thus Mr. Sheriff has had the good fortune to
raise in his lifetime seven new varieties, which are now extensively
grown in many parts of Britain.[550]

As in the case of many other plants, some varieties, both old and new,
are far more constant in character than others. Colonel Le Couteur was
forced to reject some of his new sub-varieties, which he suspected had
been produced from a cross, as incorrigibly sportive. With respect to
the tendency to vary, Metzger[551] gives from his own experience some
interesting facts: he describes three Spanish sub-varieties, more
especially one known to be constant in Spain, which in Germany assumed
their proper character only during hot summers; another variety kept
true only in good land, but after having been cultivated for
twenty-five years became more constant. He mentions two other
sub-varieties which were at first inconstant, but subsequently became,
apparently without any selection, accustomed to their new homes, and
retained their proper character. These facts show what small changes in
the conditions of life cause variability, and they further show that a
variety may become habituated to new conditions. One