Down, April 30th [1868].

Your letter, like so many previous ones, has interested me much. Dr.
Allbutt's view occurred to me some time ago, and I have written a short
discussion on it. It is, I think, a remarkable law, to which I have found
no exception. The foundation lies in the fact that in many cases the eggs
or seeds require nourishment and protection by the mother-form for some
time after impregnation. Hence the spermatozoa and antherozoids travel in
the lower aquatic animals and plants to the female, and pollen is borne to
the female organ. As organisms rise in the scale it seems natural that the
male should carry the spermatozoa to the female in his own body. As the
male is the searcher, he has required and gained more eager passions than
the female; and, very differently from you, I look at this as one great
difficulty in believing that the males select the more attractive females;
as far as I can discover, they are always ready to seize on any female, and
sometimes on many females. Nothing would please me more than to find
evidence of males selecting the more attractive females. I have for months
been trying to persuade myself of this. There is the case of man in favour
of this belief, and I know in hybrid unions of males preferring particular
females, but, alas, not guided by colour. Perhaps I may get more evidence
as I wade through my twenty years' mass of notes.

I am not shaken about the female protected butterflies. I will grant (only
for argument) that the life of the male is of very little value,--I will
grant that the males do not vary, yet why has not the protective beauty of
the female been transferred by inheritance to the male? The beauty would
be a gain to the male, as far as we can see, as a protection; and I cannot
believe that it would be repulsive to the female as she became beautiful.
But we shall never convince each other. I sometimes marvel how truth