is, with modifications brought about by use, and it is to these ALONE that
the Lamarckian principle refers.

III. OBJECTIONS TO THE THEORY OF SELECTION.

(a) Saltatory evolution.

The Darwinian doctrine of evolution depends essentially on THE CUMULATIVE
AUGMENTATION of minute variations in the direction of utility. But can
such minute variations, which are undoubtedly continually appearing among
the individuals of the same species, possess any selection-value; can they
determine which individuals are to survive, and which are to succumb; can
they be increased by natural selection till they attain to the highest
development of a purposive variation?

To many this seems so improbable that they have urged a theory of evolution
by leaps from species to species. Kolliker, in 1872, compared the
evolution of species with the processes which we can observe in the
individual life in cases of alternation of generations. But a polyp only
gives rise to a medusa because it has itself arisen from one, and there can
be no question of a medusa ever having arisen suddenly and de novo from a
polyp-bud, if only because both forms are adapted in their structure as a
whole, and in every detail to the conditions of their life. A sudden
origin, in a natural way, of numerous adaptations is inconceivable. Even
the degeneration of a medusoid from a free-swimming animal to a mere brood-
sac (gonophore) is not sudden and saltatory, but occurs by imperceptible
modifications throughout hundreds of years, as we can learn from the
numerous stages of the process of degeneration persisting at the same time
in different species.