The whole structure of the creature is for movement. He has no brain, only a cluster of nerves somewhat like one; no heart, only a segmented tube, in which a white blood circulates; no distinct lungs, but air-chambers throughout the whole body, so that it is easily poised amid the aerial waves, as he glides, or flutters securely above the earth. There are many muscles, two or three pairs of legs, and about five pairs of hooked arrangements called pro-legs; and his glory lies in his four broad wings of radiant colors, covered with silvery and shining plumes of softest texture. These wings are to him as the knight's steed, bearing him proudly in his circling combats with his rivals, or in his sportive ascents with his mate, or on his gay journeys with a crowd of winged comrades along the aerial highroads. He need not _seek_ adventures, for when he is a butterfly he has already passed through wonderful experiences. His life begins with a tiny egg, the size of a pin-head, laid singly on the _under_ side of a leaf for protection. Every species of butterfly has its own special food-plants, and will feed from no others; but do not imagine that the pastures of our _Troilus_ are limited. He feeds upon two of the largest and most beautiful tree families--the _Rosaceæ_ and the _Lauraceæ_--beautiful for fruit, flower, foliage and fragrance. With the rose family alone the range is immense, embracing, as it does, not only the rose, but the hawthorn, the meadow-sweet, the mountain ash, the strawberry, the cherry, apple and all the lovely orchard trees, while with the other family we find the glossy and shining leaf of the magnolia tribe, and the aromatic odors of sassafras and spice-wood. The butterfly eggs are marvels of color, pale green or white at first, changing to all sorts of iridescent tints as the life inside matures, and also of form, for they mimic the delicate sea-fashions of urchin and coral, the richness of oriental mosques, and the intricacy of design in Gothic windows.