'In the old aphorism, nature is always self-similar. In the plant, the eye or germinative point opens to a leaf, then to another leaf, with a power of transforming the leaf into radicle, stamen, pistil, petal, bract, sepal, or seed. The whole art of the plant is still to repeat leaf on leaf without end, the more or less of heat, light, moisture, and food, determining the form it shall assume. In the animal, nature makes a vertebra, or a spine of vertebræ, and helps herself still by a new spine, with a limited power of modifying its form,--spine on spine, to the end of the world. A poetic anatomist, in our own day, teaches that a snake being a horizontal line, and man being an erect line, constitute a right angle; and between the lines of this mystical quadrant, all animated beings find their place: and he assumes the hair-worm, the span-worm, or the snake, as the type or prediction of the spine. Manifestly, at the end of the spine, nature puts out smaller spines, as arms; at the end of the arms, new spines, as hands; at the other end she repeats the process, as legs and feet. At the top of the column she puts out another spine, which doubles or loops itself over, as a span-worm, into a ball, and forms the skull, with extremities again: the hands being now the upper jaw, the feet the lower jaw, the fingers and toes being represented this time by upper and lower teeth. This new spine is destined to high uses. It is a new man on the shoulders of the last.' [221] As one reads this it might be asked, How could its idealism be more profoundly pictured for the eye than in the Serpent coiled round the egg,--the seed out of which all these spines must branch out for their protean variations? What refrains of ancient themes subtly sound between the lines,--from the Serpent doomed to crawl on its belly in the dust, to the Serpent that is lifted up! Now let us turn to the page of Jules Michelet, and read what the Serpent signified to one mood of his sympathetic nature. 'It was one of my saddest hours when, seeking in nature a refuge from thoughts of the age, I for the first time encountered the head of the viper. This occurred in a valuable museum of anatomical imitations.