“Dear Sir, yours faithfully,
“Ch. Darwin.”
* * * * *
“Sept. 22nd [1877].
“Down.
“My dear Sir—I am doubtful whether speculations in a letter ought to be published, especially after a long interval of time. Any fact which he states, I feel pretty sure he would not at all object being used by anyone.—Pray do the best you can.—I should grieve beyond measure to be accused of a breach of confidence.—He has lately, as I mentioned, thrown much light on the first steps in mimicry.
“With respect to dimorphic Butterflies, those about which I have read appear at different seasons, and have been the subject of an admirable essay by Prof. Weismann. It is some little time since I read the essay and one subject drives another out of my head, but I think he explains all such cases by the direct inherited effects of temperature. He tried experiments. If you read German, I believe I could find Weismann’s essays and lend them to you. In your present interesting case I really do not know what to think: it seems rather bold to attribute the 2 coloured forms to nat. selection, before some advantage can be pointed out.—May not the female revert in some cases? I do not doubt that the intermediate form could be eliminated as you suggest.
“I wish that my opinion could have been of any value....
“I remain yours very faithfully,
“Ch. Darwin.”
This last letter, with others that followed it, directing Meldola’s attention to Weismann’s “Studies in the Theory of Descent,” resulted in the English translation which is so admirably rendered and edited. Many of the later letters are concerned with the progress of this publication. The remarks about dimorphic butterflies referred to Meldola’s observation, that in one of those years in which Colias edusa was extremely abundant, a whole series of forms had been taken transitional between the normal orange female and the white variety helice:—
“Sept. 27 [1877].