Dear Mr. Darwin

Some years ago I imported from France a lot of Ranæ esculentæ and put them into a pond at Woburn Abbey, where they have done very well & increased in numbers, and where their croaking charms me every summer.¹ I observed that some of the females were compelled to submit in the spring to the rude embraces of common English toads² & I expected that the discovery of a new species of batrachian in Bedfordshire would be announced some day. Being at Woburn during the Easter holidays I observed a French frog who had copulated with a female toad— I took them home & kept them till the toad had spawned. I brought the spawn with me but though it has not yet decayed it does not seem to develop. I want to ask you whether you know of any experiments in crossing frogs & toads or R. esculenta with R. temporaria, our common frog? I think I remember reading that Spallanzani tried these experiments long ago without success.³

Excuse the liberty I have taken and believe me | y^rs. sincerely | Arthur Russell