55 But you wonder how what has yielded to putrefaction can again become solid, how scattered particles can come together, those that are consumed be made good: you do not wonder how seeds broken up under the moist pressure of the earth grow green. For certainly they too, rotting under contact with the earth, are broken up, and when the fertilising moisture of the soil gives life to the dead and hidden seeds, and, by the vital warmth, as it were breathes out a kind of soul of the green herb. Then little by little nature raises from the ground the tender stalk of the growing ear, and as a careful mother folds it in certain sheaths, lest the sharp ice should hurt it as it grows, and to protect it from too great heat of the sun; and lest after this the rain should break down the fruit itself escaping as it were from its first cradle and just grown up, or lest the wind should scatter it, or small birds destroy it, she usually hedges it around with a fence of bristling awn.
Source: On the Death of Satyrus (New Advent)