s is the foundation of all good work; but I must look at such
papers as yours in Silliman as the fruit. As careful observation is far
harder work than generalisation, and still harder than speculation, do
you not think it very possible that it may be overvalued? It ought never
to be forgotten that the observer can generalise his own observations
incomparably better than any one else. How many astronomers have
laboured their whole lives on observations, and have not drawn a single
conclusion; I think it is Herschel who has remarked how much better it
would be if they had paused in their devoted work and seen what they
could have deduced from their work. So do pray look at this side of the
question, and let us have another paper or two like the last admirable
ones. There, am I not an audacious dog!

You ask about my doctrine which led me to expect that trees would tend
to have separate sexes. I am inclined to believe that no organic being
exists which perpetually self-fertilises itself. This will appear very
wild, but I can venture to say that if you were to read my observations
on this subject you would agree it is not so wild as it will at first
appear to you, from flowers said to be always fertilised in bud, etc. It
is a long subject, which I have attended to for eighteen years. Now, it
occurred to me that in a large tree with hermaphrodite flowers, we will
say it would be ten to one that it would be fertilised by the pollen of
its own flower, and a thousand or ten thousand to one that if crossed
it would be crossed only with pollen from another flower of same tree,
which would be opposed to my doctrine. Therefore, on the great principle
of "Nature not lying," I fully expected that trees would be apt to be
dioecious or monoecious (which, as pollen has to be carried from flower
to flower every time, would favour a cross from another individual of
the same species), and so it seems to be in Britain and New Zealand. Nor
can the fact be explained by certain families having this structure
and chancing to be trees, for the rule seems to hold both in genera and
families, as well as in species.

I give you full permission to laugh your fill at this wild speculation;
and I do not pretend but what it may be chance which, in this case, has
led me apparently right. But I repeat that I feel sure that my doctrine
has more probability than at first it appears to have. If you had not
asked, I should not have written at such length, th