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Vries, Hugo de, 1848-1935

"Species and Varieties, Their Origin by Mutation"

Wholly filled circles of secondary capsules
without gaps give the two last degrees, the fifth requiring only
continuity of the circle, the sixth displaying a large and bright crown
all around the central head. The fifth group ordinarily includes from
90-100 altered stamens, while the sixth has from 100-150 of these
deviating parts.
In ordinary cultures the third and fourth group, with their interrupted
crowns, predominate. Large crowns are rare and flowers which at first
sight seem to be wholly normal, occur only under circumstances
definitely known to be unfavorable to growth, and to the development of
the anomaly.
Having reached by this means a very simple and easy method of stating
the facts shown by equal lots under contrasting influences, we will now
make use of it to inquire into the relation [378] of this exceptionally
high degree of variability to the inner and outer conditions of life.
As a rule, all experiments show the existence of such a relation.
Unfavorable conditions reduce the numbers of altered stamens, favorable
circumstances raise it to its highest point. This holds true for lots
including hundreds of specimens, but also for the sundry heads of one
bed, and often for one single plant.
We may compare the terminal flower with those of the lateral branches on
a plant, and when no special influences disturb the experiment, the
terminal head ordinarily bears the richest crown.


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