Origin of Species Variorum

shaped pieces of bone? As Owen has remarked, the benefit derived from the yielding of the separate pieces in the act of parturition of mammals, will by no means explain the same construction in the skulls of birds and reptiles. Why should similar bones have been created to form the wing and the leg of a bat, used as they are for such totally different purposes? Why should one crustacean, which has an extremely complex mouth formed of many parts, consequently always have fewer legs; or conversely, those with many legs have simpler mouths? Why should the sepals, petals, stamens, and pistils, in each flower, though fitted for such widely different purposes, be all constructed on the same pattern?

On the theory of natural selection, we can ... answer these questions. In the vertebrata, we see a series of internal vertebræ bearing certain processes; in the articulata, the body divided into a series of segments, bearing external appendages; and in flowering plants, spiral whorls of leaves. ↑ An indefinite repetition of the same part or organ is the common characteristic, as Owen has observed, of all low or little modified forms; therefore ... the unknown progenitor of the vertebrata no doubt possessed many vertebræ; the unknown progenitor of the articulata, many segments; and the unknown progenitor of flowering plants, many leaves arranged in one or more spires. We have formerly seen that parts many times repeated are eminently liable to vary in number and structure. Consequently such parts being already present, and being highly variable, would afford the materials for adaptation to the most different purposes; and they would generally retain through the force of inheritance plain traces of their original or fundamental resemblance. ↑

In the great class of molluscs, though it can easily be shown that the