One of the most elaborate of these
experiments was conducted by a German botanist, who transplanted 2,500
different kinds of mountain plants to the lowlands, where he studied
them for several years alongside their relatives, natives of these
lowlands. He found that their mountain environment had made absolutely
no permanent change in their structures or habits, which soon conformed
exactly with those of their relatives which had lived in the lowland
environment for centuries. Many similar efforts have been made to
confirm this doctrine of the transmission of acquired characters; but
their universal failure is like that of mechanics in trying to invent
perpetual motion.
Thomas Hunt Morgan sums up the present situation in the following words:
"To-day the theory has few followers among trained investigators, but it
still has a popular vogue that is wide-spread and vociferous." And we
may add that the extent of its spread is directly proportioned to the
need felt for this doctrine as a support of the theory of evolution,
while the vociferance of its advocates is inversely proportioned to the
evidence in its support.
As a result of extensive modern experiments and discussion, biologists
have grown very cautious, and are by no means so positive as they were
twenty years ago in affirming just _how_ species have come into
existence.
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