sustain itself.

Haberlandt furthermore records a phenomenon perhaps analogous to this
on the grape-vine, but with this exception the case described by him is
unique. In order to pass any further judgment regarding it, we should
have to ascertain whether the whole phenomenon is not a case of
so-called adaptation; if so, processes should be found in nature,
analogous to the poisoning of the hydathodes in this experiment, which
result in the destruction of the hydathodes so that in consequence the
plant would have gained the power of making good the loss, by means of
the substitute organs. Such processes, however, (even through poisoning
or through parasites) would be very highly improbable. Equally
incredible is the alternative possibility that the new organs would be
produced by the plant not as a substitute but as a supplementary
apparatus when the old ones would not suffice for secretion in case of
very large absorption of water. This also must doubtlessly be rejected,
as Haberlandt has observed.

Powers of adaptation should, of course, according to Darwinism, be
gradually acquired in the struggle for existence, as in that case they
should also have stability; but since this is not possessed by the new
organs, the presumption is that they do not possess the character of
adaptation. They are therefore new organs that originated after an
entirely unnatural and unforeseen interference with the normal vital
functions and in consequence of a self-regulating activity of the
organism.

What then is there in the whole phenomenon worthy of notice with regard
to the theory of Descent?

1. An immediately well adapted new organ has here originated very
suddenly without any previous incipient formation, without gradual
perfection and without stages of transition.

2. In its formation struggle for existence and natural selection are
entirely excluded, neither can find any application whatever even
according to the newer exposition of Weismann. Haberlandt himself draws
this conclusion.

3. If this phenomenon of a suddenly appearing change can take place in
the course of the development of the individual, there can be no
obvious reason why it should not take place in the same manner (without
natural selection or struggle for existence) in the course of the
phylogenetic development.

It is manifestly of the greatest importance that in this case a direct,
experimental proof has been given that an organ has originated suddenly