348 READINGS IN EVOLUTION, GENETICS, AND EUGENICS 
circle of smaller branches, growing upwards from its base so as to form 
a dense brush. .... The flowers are large and bright yellow attract- 
ing immediate attention even from a distance. They open toward 
evening, as the name indicates, and are pollinated by bumble-bees 
and moths.” 
On account of the classic character of De Vries’s mutants of 
Oenothera lamarckiana we shall follow his own detailed description 
of the more significant of these.—Eb.] 
NEW SPECIES (MUTANTS) OF OENOTHERA? 
HUGO DE VRIES 
This striking species (Oenothera lamarckiana) was found in a 
locality near Hilversum, in the vicinity of Amsterdam, where it grew 
in some thousands of individuals. Ordinarily biennial, it produces 
roset es in the first, and stems in the second year. Both the stems 
and the rosettes were at once seen to be highly variable, and soon 
distinct varieties could be distinguished among them. 
The first discovery of this locality was made in 1886. Afterwards 
I visited it many times, often weekly or even daily during the first 
few years, and always at least once a year up to the present time. 
This stately plant showed the long-sought peculiarity of producing a 
number of new species every year. Some of them were observed 
directly on the field, either as stems or as rosettes. The latter could 
be transplanted into my garden for further observation, and the stems 
yielded seeds to be sown under like control. Others were too weak 
to live a sufficiently long time in the field. They were discovered by 
sowing seed from indifferent plants of the wild locality in the 
garden. A third and last method of getting still more new species 
from the original strain was the repetition of the sowing process, by 
saving and sowing the seed which ripened on the introduced plants. 
These various methods have led to the discovery of over a dozen new 
types never previously observ:d or described. 
Leaving the physiological side of the relations of these new forms 
for the next lecture, it would be profitable to give a short description 
of the several novelties. To this end they may be combined under 
five different heads, according to their systematic value. The first 
head includes those which are evidently to be considered as varieties, 
« From H. De Vries, Species and Varieties (copyright 1904). Used by special 
permission of the publishers, The Open Court Publishing Company. 
