From Arthur Russell   19 May 1873

Dear Mr. Darwin,

I venture to send you the following note for a future edition of your “animals under domestication” Vol. II p. 236 you say that “distinct races of carp have not been formed &c”¹

In Germany where carp ponds exist on most large estates & many books have been written on the management of fish ponds, they cultivate a very distinct & constant variety of carp which has been made into a species (Cyprinus Rex cyprinorum C. macrolepidotus &c) & which fetches a higher price in the market & is more valued for the table than the Common carp— the Germans call it Spiegelkarpfe   You may see a figure of it in Bloch.² In this variety the scales have nearly disappeared, the fish is covered with a leathery skin & the few scales that persist along the dorsal line and on the sides of the fish attain a large development like half crown pieces. Occasionally the scales are wanting entirely & then the fish is called: leather-carp (C. nudus, C. coriaceus) Cyprinus Alepidotus) Lederkarpfen in German.³ Great care is taken to prevent them mixing with the common scaly carp. I brought 32 small Spiegelcarp living from Berlin— they are now in a pond by themselves at Woburn Abbey, Beds⁴

believe me truly yours | Arthur Russell.