To Mary Anne Theresa Whitby1 2 September [1847]
Down Farnborough Kent
Sept 2d
Dear Madam
Your great kindness in giving me last year at Southampton2 information on the varieties on the silk-worm, makes me venture once again to trouble you. My question is a very simple one, and yet I am very curious to have it answered on the best authority.— Whenever I have observed the moths raised from silk-worm kept by children, the wings have been more or less crumpled, & I have been assured that they can never fly. Does this hold good, especially in France & Italy? If it does, can you, inform me, whether the males & females are equally helpless as regards flight?3 I presume that they are in the same condition, as our domestic ducks, & I should be extremely grateful for any information on this point.—
You were so kind last year as to give me hopes that you would try two experiments on hereditariness (a point on which I am particularly interested) in the caterpillar state: the first was whether the black eye-browed kind would produce black or dark-eyed caterpillar children:4 the second was to see if the very fat caterpillars (which I think you called Frales & which you described to me in a very laughable manner) would produce moths; & if so whether their offspring would be likewise fat & silkless.—5 I can really hardly say, how grateful I should be to know the results of such experiments; for in a work which I intend some few years hence to publish on variation, there will be hardly any facts in the insect world.
Will you permit me one other question, namely whether you have ever observed any difference in habits, such as in manner of crawling, eating, spinning &c in the caterpillars of the different breeds, which you have kept.— I am well aware I have much reason to apologise for thus presuming to trouble you, & I can only trust to your kindness to excuse.
Pray believe, dear Madam, with much respect. | Your sincerely obliged | Charles Darwin
Footnotes
Bibliography
Colp, Ralph, Jr. 1972. Charles Darwin and Mrs. Whitby. Bulletin of the New York Academy of Medicine 2d ser. 48: 870–6.
Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.
Whitby, Mary Anne Theresa. 1846. On the cultivation of silk in England. Report of the 16th meeting of the British Association for the Advancement of Science held at Southampton, pt 2, pp. 87-8.
Whitby, Mary Anne Theresa. 1848. A manual for rearing silkworms in England: with a brief notice on the cultivation of the mulberry tree. London.
Summary
Questions Mrs W on difference in flight capacity of male and female silkworm moths and asks her for results of experiments he suggested she do with silkworms to determine hereditariness of dark "eyebrows". [See Variation 1: 302.]
Letter details
- Letter no.
- DCP-LETT-1113
- From
- Charles Robert Darwin
- To
- Mary Anne Theresa Whitby
- Sent from
- Down
- Source of text
- American Philosophical Society (Mss.B.D25.61)
- Physical description
- ALS 3pp
Please cite as
Darwin Correspondence Project, “Letter no. 1113,” accessed on 26 September 2022, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-1113.xml
Also published in The Correspondence of Charles Darwin, vol. 4