Basidiomycete fungi (mushrooms, rusts, smuts) launch spores via the Buller's drop mechanism — arguably the smallest catapult in nature. A water droplet condenses at the spore-sterigma junction; as it grows, surface tension snaps the spore away at accelerations up to 10,000 g, reaching initial velocities of ~1 mm/s. This ejects spores 0.1–1 mm — just far enough to escape the still-air layer near the cap. Once airborne, Stokes' law governs settling velocity: v_s = (2r²Δρg)/(9η). Spores 2–20 μm in diameter can remain airborne for hours, travelling hundreds of kilometers. Germination requires the right temperature (~20°C optimal) and humidity (>85% for most species).