the right time, and I think Romanes' ponderous paper is disposed of.

I wrote my paper, however, quite as much to expose the great presumption
and ignorance of Romanes in declaring that Natural Selection is _not_ a
theory of the origin of species--as it is calculated to do much harm.
See, for instance, the way the Duke of Argyll jumped at it like a trout
at a fly!--Yours very faithfully,

ALFRED R. WALLACE.

* * * * *

The earlier part of the next letter refers to "The Experimental Proof of
the Protective Value of Colour and Markings in Insects in reference to
their Vertebrate Enemies," in the _Proceedings of the Zoological Society
of London_, 1887, p. 191.

TO PROF. POULTON


_Frith Hill, Godalming. October 20, 1887._

My dear Poulton,--It is very interesting to me to see how very generally
the facts are in accordance with theory, and I am only surprised that
the exceptions and irregularities are not more numerous than they are
found to be. The only difficult case, that of _D. euphorbiæ_, is due
probably to incomplete knowledge. Are lizards and sea-birds the only, or
even the chief, possible enemies of the species? They evidently do not
prevent its coming to maturity in considerable abundance, and it is
therefore no doubt preserved from its chief enemies during its various