(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.
LETTER 310. TO R. MELDOLA. Down, February 2nd, 1882.
I am very sorry that I can add nothing to my very brief notice, without reading again Weismann's work and getting up the whole subject by reading my own and other books, and for so much labour I have not strength. I have now been working at other subjects for some years, and when a man grows as old as I am, it is a great wrench to his brain to go back to old and half- forgotten subjects. You would not readily believe how often I am asked questions of all kinds, and quite lately I have had to give up much time to do a work, not at all concerning myself, but which I did not like to refuse. I must, however, somewhere draw the line, or my life will be a misery to me.
I have read your preface, and it seems to me excellent. (310/1. "Studies in the Theory of Descent." By A. Weismann. Translated and Edited by Raphael Meldola; with a Prefatory Notice by C. Darwin and a Translator's Preface. See Letter 291.) I am sorry in many ways, including the honour of England as a scientific country, that your translation has as yet sold badly. Does the publisher or do you lose by it? If the publisher, though I shall be sorry for him, yet it is in the way of business; but if you yourself lose by it, I earnestly beg you to allow me to subscribe a trifle, viz., ten guineas, towards the expense of this work, which you have undertaken on public grounds.
LETTER 311. TO W. HORSFALL. Down, February 8th, 1882.
In the succession of the older Formations the species and genera of trilobites do change, and then they all die out. To any one who believes that geologists know the dawn of life (i.e., formations contemporaneous with the first appearance of living creatures on the earth) no doubt the sudden appearance of perfect trilobites and other organisms in the oldest known life-bearing strata would be fatal to evolution. But I for one, and many others, utterly reject any such belief. Already three or four piles of unconformable strata are known beneath the Cambrian; and these are generally in a crystalline condition, and may once have been charged with organic remains.
With regard to animals and plants, the locomotive spores of some algae, furnished with cilia, would have been ranked with animals if it had not been known that they developed into algae.
LETTER 312. TO JOHN COLLIER. Down, February 16th, 1882.
I must thank you for the gift of your Art Primer, which I have read with much pleasure. Parts were too technical for me who could never draw a line, but I was greatly interested by the whole of the first part.