From John Brigg   6 July 1877

Keighley

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).

Please cite as “DCP-LETT-11037,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-11037