ord that you say, and it could not be
expressed more clearly or vigorously. After the Duke's last letter and
flourish about me I thought it paltry not to say that I agreed with what
you had said. But after writing two folio pages I find I could not say
what I wished to say without taking up too much space; and what I had
written did not please me at all, so I tore it up, and now by all the
gods I rejoice that I did so, for you have put the case incomparably
better than I had done or could do.

Moreover, I hate controversy, and it wastes much time, at least with a
man who, like myself, can work for only a short time in a day. How in
the world you get through all your work astonishes me.

Now do not make me feel guilty by answering this letter, and losing some
of your time.

You ought not to swear at Roux's book, which has led you into this
controversy, for I am sure that your last letter was well worth
writing--not that it will produce any effect on the Duke.

LETTER 309. TO J. JENNER WEIR.

(309/1. On December 27th, 1881, Mr. Jenner Weir wrote to Mr. Darwin:
"After some hesitation in lieu of a Christmas card, I venture to give
you the return of some observations on mules made in Spain during the
last two years...It is a fact that the sire has the prepotency in
the offspring, as has been observed by most writers on that subject,
including yourself. The mule is more ass-like, and the hinny more
horse-like, both in the respective lengths of the ears and the shape of
the tail; but one point I have observed which I do not remember to have
met with, and that is that the coat of the mule resembles that of its
dam the mare, and that of the hinny its dam the ass, so that in this
respect the prepotency of the sexes is reversed." The hermaphroditism in
lepidoptera, referred to below, is said by Mr. Weir to occur notably in
the case of the hybrids of Smerinthus populi-ocellatus.)

Down, December 29th, 1881.

I thank you for your "Christmas card," and heartily return your good
wishes. What you say about the coats of mules is new to me, as is the
statement about hermaphroditism in hybrid moths. This latter fact seems
to me particularly curious; and to make a very wild hypothesis, I should
be inclined to account for it by reversion to the primordial condition
of the two sexes being united, for I think it certain that hybridism
does lead to reversion.

I keep fairly well, but have not much strength, and feel very old.

L