d divided. I must have been cracked to have written it, for I have no
evidence, without a person be willing to admit all my views, and then it
does follow.

(14/5. The remainder of the foregoing letter is published in the "Life
and Letters," II., page 29. It is interesting as giving his views on
the mutability of species. Thus he wrote: "With respect to books on this
subject, I do not know any systematical ones, except Lamarck's, which is
veritable rubbish; but there are plenty, as Lyell, Pritchard, etc., on
the view of the immutability." By "Pritchard" is no doubt intended James
Cowles "Prichard," author of the "Physical History of Mankind." Prof.
Poulton has given in his paper, "A remarkable Anticipation of Modern
Views on Evolution" (14/6. "Science Progress," Volume I., April 1897,
page 278.), an interesting study of Prichard's work. He shows that
Prichard was in advance of his day in his views on the non-transmission
of acquired characters. Prof. Poulton also tries to show that Prichard
was an evolutionist. He allows that Prichard wrote with hesitation, and
that in the later editions of his book his views became weaker.
But, even with these qualifications, we think that Poulton has
unintentionally exaggerated the degree to which Prichard believed in
evolution.

One of Prichard's strongest sentences is quoted by Poulton (loc. cit.,
page 16); it occurs in the "Physical History of Mankind," Ed. 2, Volume
II., page 570:--

"Is it not probable that the varieties which spring up within the
limits of particular species are further adaptations of structure to
the circumstances under which the tribe is destined to exist? Varieties
branch out from the common form of a species, just as the forms of
species deviate from the common type of a genus. Why should the
one class of phenomena be without end or utility, a mere effect of
contingency or chance, more than the other?"

If this passage, and others similar to it, stood alone, we might agree
with Prof. Poulton; but this is impossible when we find in Volume I.
of the same edition, page 90, the following uncompromising statement of
immutability:--

"The meaning attached to the term species, in natural history, is
very simple and obvious. It includes only one circumstance--namely, an
original distinctness and constant transmission of any character. A race
of animals, or plants, marked by any peculiarities of structure which
have always been constant and undeviating, constit