Illustration by Friedrich Specht, engraved by Carl Gottlob Specht (from mark), for Brehm’s Life of Animals: A Complete Natural History for Popular Home Instruction and for the Use of Schools, vol. 1, Mammalia, by Dr. Alfred Edmund Brehm, 1895. Digitized by the Internet Archive from the collection of the American Museum of Natural History. (In the public domain.) <https://www.archive.org/details/brehmslifeofanim00breh/page/551>
━━━━━━━━━━━━━━━━━━━━
“Hippopotamus,” illustration by Friedrich Specht for Illustrated Natural History (Animals and Birds): Arranged for Young Readers, by Rev. J. G. Wood, 1899, as reprinted in Children’s Own Library, vol. 10, Miscellaneous Tales, ed. by J. Ellis Burdick, 1910. Digitized by the Internet Archive from the collection of the University of North Carolina at Chapel Hill. (In the public domain.) <https://www.archive.org/details/childrensownlibr10burd/page/108>