To M. J. Berkeley   10 July 1875

Down, | Beckenham, Kent.

July 10 1875

My dear Sir

I hope that you will forgive me for troubling you, but if you are much engaged or not well, pray do not answer me, & I shall understand the reason.1

I am very curious to learn, owing to some correspondence with Sir J. Paget on contagion, whether fairy rings start from a central point & spread outwards, or whether they commence as rings.2 In this latter case what can the cause be? If they spread outwards, is any thing known of the rate of spreading?

Lastly, is it known on what the Mycelium subsists?3

Pray forgive me for being so troublesome, & believe me, with much respect | yours sincerely | Ch. Darwin

For Berkeley’s reply, see Correspondence vol. 23, letter from M. J. Berkeley, 13 July 1875.
Mycelium is the vegetative part of a fungus, characterised by fine branching threads or hyphae; in fungi that form rings, the underground hyphae spread in a circular shape, and mushrooms appear above ground at the edge of the circle.

Please cite as “DCP-LETT-10055F,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-10055F