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Darwin Correspondence Project

From John Brigg   6 July 1877


July 6th. 1877

C. Darwin Esqre

Dear Sir

Many thanks for the account of Pouchet’s experiments1   the information is exactly what I wanted. I am not yet in a position to dispute his conclusions but I think I can prove a few more points beyond those which he mentions. My fish are the ordinary Gold Fish (Carp,2 in our mill ponds we breed large numbers   a proportion are dark coloured placing these in a white vase with bright sunlight they become yellow. I have been led into this by finding that the introduction of a weed into one pond prevented the fish from changing to Golden or White   the same fish in another pond; where the water is too hot for the weed to grow: are almost all Gold yellow or white.

If you have any interest in the experiments I shall be glad to inform you of their results.

I remain | Dear Sir | Yours ms truly | John Brigg—

I have two Alligators now about 3 feet long, which I keep in the mill ponds. I have good opportunity for noting their habits should you wish to know about them

CD annotations

Top of letter: ‘[has] Pouchets papers’ pencil


No other correspondence between CD and Brigg has been found. Félix Archimède Pouchet’s claim to have produced unicellular organisms through spontaneous generation was published in Pouchet 1859.
Goldfish (Carassius auratus) are in family Cyprinidae (carps and minnows).


Pouchet, Félix Archimède. 1859. Hétérogénie ou traité de la génération spontanée. Paris: J. B. Baillière.


Thanks CD for account of F. A. Pouchet’s experiments. Cannot yet dispute his conclusions.

Continues experiments on the colour of goldfish as affected by light and presence of plants.

Letter details

Letter no.
John Brigg
Charles Robert Darwin
Sent from
Source of text
DAR 160: 309
Physical description
ALS 2pp †

Please cite as

Darwin Correspondence Project, “Letter no. 11037,” accessed on 1 October 2023,