The Bamberg herald. [volume] (Bamberg, S.C.) 1891-1972, 1906-05-17
EVOLUTION 51:siss Srxas + sseeiissis|ss. nfxsiss
By DIR. HUGO DE VRIES.
Il II - - - u

by an ample critical survey Of the his
torical evidence, that sudden sports are
the prevailing rule and probably even
the exclusive manner of originating
new varieties.
Such considerations have led to the
conviction that what occurs i'll horticul-
ture must also occur in the expert
mental garden. If the conditions are
the same, why should not the phenom-
ena be the same, TOO? If mutations
are rare in horticulture, the expert
menter has only to arrange his work
so as to be able to detect rare occur
rences in his cultures. too. In doing
this have succeeded in observing mu-
tations quite analogous to the horti-
cultural instances and collecting all the
evidence concerning their ancestry and
their descendants, as we'll as concern
ing the mode of their appearance.
Moreover, 1 have had the good for
tune of discovering wild plant which
is even yet in condition Of mutability.
Yearly it is observed to produce new
species. 1t is the large Towering even
ing primsose, which bears the name Of
Lamarck, the founder Of the theory
of evolution. It clearly shows how
new species arise from an old stock
not by continuous and slow changes
but suddenly. The stock itself Is not
altered by the process nor even notice
ably diminished. The new species
which it produces arise on all sides.
Some of them are in higher, others
in lesser degree, fit for their life con-
ditions; some persist during years.
while others disappear nearly as soon
as they arise. 8
This instance of experimental muta-
ton Is found largely to agree with the
experience of breeders, especially In
horticulture, and likewise with the
conclusions that have been drawn from
comparative studies. The assumption
that those species and genera which
now consist of large groups of closely
allied forms have originated In the
same way seems quite undeniable; and
as soon as the validity Of this general
ization is granted for these cases 1t
will have to be considered Of general. II
not universal, bearing.
Two main lines have to be distin-,
gushed: to study the phenomenon it.
self and that Of its causes. Mutations.
Of course, cannot be assumed to be a
special feature Of the evening prin1-
roses. They must occur elsewhere, too.
and these must be sought. One or
two novelties among thousands Of in-
diyiduals of the common type are nos
easily found, especially where the diff
ferences are slight and new and there
by apt to be overlooked. No differ
'entiating remarks, however slight,
should be considered as Insignificant.
All aberrant individuals should be
planted separately and protected with
all the care required to insure the full
est development. Many Of them after
ward prove to be only fluctuating Tari-
ants or to have deceived the expert
menter. They are simply discarded.
It is quite sufficient if some remain
and prove to be mutants. AS soon as
in this manner a mutable strain will be
discovered, the greater part Of the
other species may be excluded, al
though the search for new mutable
species should never be wholly neg
lected. Each year some new forms
should be taken into culture, in order
to have sufficient chances Of grad
ually increasing the evidence concern
ing the occurrence Of mutability In ma
ture.
The chief objects Of this inquiry,
however, must be study Of the mutabie
strain itself. Some Of its seeds yield
new species. while others are more con-
servative. Thence the question. Which
seeds mutate and by which causes are
they elected to do so? The location OF
the mutating seeds within the fruit,
the position CT the preferred fruits on
the spikes, the influence Of the indi-
vidual strength of the sundry branches
and many other points have to be in
vestigated. Further, it is probable
that the degree of mutability, or. in
other words, the yield Of mutatins
seeds, is more or less dependent on the
outer life conditions. Thence the neceS-
sity of studying the influence Of cui-
ture in general, of light and heat, of
soil and water. and last, but not least.
Of manure. Extreme combinations OF
these factors should be tried to see
whether perhaps they may give e1-
treme results.
Underlying all and directing all the
efforts should be the hope Of obtaining
such a knowledge Of the phenomenon
as would enable US to take the whole
guidance Of it into our own hands
Scientific American.