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Darwin Correspondence Project

From Francis Darwin   [1873]

New University Club, | St. James’s Street. S.W.

Dear Father

Klein says the water ought to be changed every day1   I should think you might draw if off with a syphon, which Jim could rig up with glass tubing & indiarubber ditto— I found I could pour off a good deal of water by stretching a bit of gauze over the lip of the basin.


I left a bit I used on the fern heap in Deadman’s corner; but I should think the syphon wd be best— Please tell G the Revalenta shop is shut today.2 Klein says his discovery about toads’ ova does not bear on pangenesis.3 I don’t know why he said it was good for you.

Yr affec | Frank Darwin


Edward Emanuel Klein was a bacteriologist and histologist. The experiment has not been identified. Jim was Horace Darwin’s nickname.
Francis probably refers to George Howard Darwin. Revalenta was a mixture of lentil and barley meal, sold as a health food (Hassall 1855, pp. 237–50).
The discovery has not been identified. For CD’s hypothesis of pangenesis, see Variation 2: 357–404.


Hassall, Arthur Hill. 1855. Food and its adulterations: comprising the reports of the Analytical Sanitary Commission of ‘The Lancet’ for the years 1851 to 1854 inclusive. London: Longman, Brown, Green, and Longmans.

Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.


Klein says water ought to be changed daily. Asks to tell G Revalenta shop shut. Klein reports discovery about toads’ ova does not bear on pangenesis.

Letter details

Letter no.
Francis Darwin
Charles Robert Darwin
Sent from
Source of text
DAR 274.1: 11
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 8713F,” accessed on 1 March 2024,

Also published in The Correspondence of Charles Darwin, vol. 21