动物志
Aristotle recorded in his "History of Animals" that the fruits of the wild fig (the caprifig) contain "psenes" (fig wasps); these begin life as grubs (larvae), and the adult "psen" splits its "skin" (pupa) and flies out of the fig to find and enter a cultivated fig, saving it from dropping. He believed that the "psen" was generated spontaneously; he did not recognise that the fig was reproducing sexually and that the "psen" was assisting in that process.