"In that great drama which we call Nature, each animal plays its especial part, and He who has adjusted and regulated everything in its due order and proportion, watches with as much care over the preservation of the most repulsive insect, as over the young brood of the most brilliant bird. Each, as it comes into the world, thoroughly knows its part, and plays it the better because it is more free to obey the dictates of its instinct. There presides over this great drama of life a law as harmonious as that which regulates the movements of the heavenly bodies; and if death carries off from the scene every hour myriads of living creatures, each hour life causes new legions to rise up in order to replace them. It is a whirlwind of being, a chain without end."