But it was in his intercourse with children that Marx was perhaps most charming. Surely never did children have a more delightful playfellow. My earliest recollection of him is when I was about three years old, and “Mohr” (the old home name will slip out) was carrying me on his shoulder round our small garden in Grafton Terrace, and putting convolvulus flowers in my brown curls. Mohr was admittedly a splendid horse.
-Eleanor Marx, "A Few Stray Notes on Karl Marx" in Reminiscences of Marx and Engels p.250
i'm not sure if there's any better copies existing online unfortunately, i pulled the quote from the copy on internet archive