same stock to diverge in character as they become modified. That
they have diverged greatly is obvious from the manner in which
species of all kinds can be classed under genera, genera under
families, families under sub-orders and so forth; and I can
remember the very spot in the road, whilst in my carriage, when
to my joy the solution occurred to me; and this was long after I
had come to Down. The solution, as I believe, is that the
modified offspring of all dominant and increasing forms tend to
become adapted to many and highly diversified places in the
economy of nature.

Early in 1856 Lyell advised me to write out my views pretty
fully, and I began at once to do so on a scale three or four
times as extensive as that which was afterwards followed in my
'Origin of Species;' yet it was only an abstract of the materials
which I had collected, and I got through about half the work on
this scale. But my plans were overthrown, for early in the
summer of 1858 Mr. Wallace, who was then in the Malay
archipelago, sent me an essay "On the Tendency of Varieties to
depart indefinitely from the Original Type;" and this essay
contained exactly the same theory as mine. Mr. Wallace expressed
the wish that if I thought well of his essay, I should sent it to
Lyell for perusal.

The circumstances under which I consented at the request of Lyell
and Hooker to allow of an abstract from my MS., together with a
letter to Asa Gray, dated September 5, 1857, to be published at
the same time with Wallace's Essay, are given in the 'Journal of
the Proceedings of the Linnean Society,' 1858, page 45. I was at
first very unwilling to consent, as I thought Mr. Wallace might