with the Duke of
Argyll (see Nature, January 16, 1890, et seq.) was that there was no
evidence in support of the transmission of any acquired
modification. The orthodoxy of science, therefore, must be held as
giving at any rate a provisional support to Professor Weismann, but
all of them, including even Professor Weismann himself, shrink from
committing themselves to the opinion that the germ-cells of any
organisms remain in all cases unaffected by the events that occur to
the other cells of the same organism, and until they do this they
have knocked the bottom out of their case.

From among the passages in which Professor Weismann himself shows a
desire to hedge I may take the following from page 170 of his book:--

"I am also far from asserting that the germ-plasm which, as I hold,
is transmitted as the basis of heredity from one generation to
another, is absolutely unchangeable or totally uninfluenced by
forces residing in the organism within which it is transformed into
germ-cells. I am also compelled to admit it as conceivable that
organisms may exert a modifying influence upon their germ-cells, and
even that such a process is to a certain extent inevitable. The
nutrition and growth of the individual must exercise some influence
upon its germ-cells . . . "

Professor Weismann does indeed go on to say that this influence must
be extremely slight, but we do not care how slight the changes
produced may be, provided they exist and can be transmitted. On an
earlier page (p. 101) he said in regard to variations generally that
we should not expect to find them conspicuous; their frequency would
be enough, if they could be accumulated. The same applies here, if
stirring events that occur to the somatic cells can produce any
effect at all on offspring. A very small effect, provided it can be
repeated and accumulated in successive generations, is all that even
the most exacting Lamarckian will ask for.

Having now made the reader acquainted with the position taken by the
leading Charles-Darwinian authorities, I will return to Professor
Weismann himself, who declares that the transmission of acquired
characters "at first sight certainly seems necessary," and that "it
appears rash to attempt to dispense with its aid." He continues:--

"Many phenomena only appear to be intelligible if we assume the
hereditary transmission of such acquired characters as the changes
which we ascribe to the use or disuse of particula