In 1874, Nature published a book review by the biologist Alfred Russel Wallace of The Naturalist in Nicaragua, in which author Thomas Belt hypothesized that leafcutter ants cultivate fungi in their nests (A. R. Wallace Nature 9, 218โ221; 1874). Later that year, it published a letter from German biologist Fritz Mรผller to Charles Darwin, confirming that leafcutter ants rely on fungal symbionts to digest the plant material they collect (F. Mรผller Nature 10, 102โ103; 1874).