In Pursuit of the Gene

REDISCOVERY © 111
those studied by Mendel. “Millardet’s hybrids are not the same cases as
those of Mendel,” he declared. To avoid any possible confusion that may
have resulted from his less than perfect command of English, he found
three different ways of saying the same thing: “The Millardet hybrids never
can be ‘disjoints’ (= split up?); all their seeds ever give the same type as
they bear themselves. Mendel’s hybrids of the first generation always split up
in the next.”
Though he had resisted spelling out his observations with Oenothera in
his first letter, rightly fearing that they would arouse the suspicions of the
highly skeptical Bateson, De Vries now came forward with his new results
that were about to appear in print. “There are very nice Millardet hybrids
in the genus Oenothera, which I have cultivated for some generations,” he
wrote, adding that “false hybrids is a bad name; they are as numerous as
true or Mendel hybrids.” Lastly, he insisted that the evidence from his
crosses was “absolutely opposed to Mendel’s law.”
Although he had been aware of the unusual behavior of his Oenothera
crosses for many years, De Vries published his results only in November
1900 in the same German journal in which he’d published his first
full treatment of Mendelism seven months earlier. 13 As he’d warned Bateson,
De Vries reported on a number of anti-Mendelian behaviors of his
Oenothera crosses, beginning with Millardet-like false crosses. Already in 1894
he crossed Oenothera lamarckiana with the pollen from the closely related variety
Oenothera biennis, and found that the resulting progeny resembled the
male parent and bred true when self-fertilized. And the same pattern was
repeated when O. lamarckiana was crossed with O. muriata, another closely related
variety, and again when O. muriata was crossed with O. biennis.
But the behavior of the Oenothera was even stranger than De Vries admitted
to Bateson. In the summer of 1898 he found that the dwarf variety
O. nanella when pollinated by O. lamarckiana gave two types of progeny, some
like the mother and some like the father, and the resulting progeny had
each bred true, and the same was true for O. lata crossed with O. lamarckiana
and for O. rubrinervis crossed with O. nanella. 14 In fact, so long as the O.
lamarckiana, or one of its mutant forms (nanella), was the pollen parent, hybrids
made from a large number of different females split into two types,