Linnaeus has calculated that if an annual plant produced only two seeds—and there is no plant so unproductive as this—and their seedlings next year produced two, and so on, then in twenty years there would be a million plants.

林奈计算过， 如果一株一年生植物只结出两颗种子——没有哪一种植物的产量比它低——而它们的幼苗明年结出两颗，依此类推，那么二十年后将有一百万株植物。