Origin of Species Variorum

Naturalists frequently speak of the skull as formed of metamorphosed vertebræ: the jaws of crabs as metamorphosed legs; the stamens and pistils of flowers as metamorphosed leaves; but it would in these cases probably be more correct, as Professor Huxley has remarked, to speak of both skull and vertebræ, both jaws and legs, &c., as having been metamorphosed, not one from the other in their present state, but from some common and simpler element. Most naturalists, however, use such language only in a metaphorical sense: they are far from meaning that during a long course of descent, primordial organs of any kind— vertebræ in the one case and legs in the other— have actually been modified into skulls or jaws. Yet so strong is the appearance of such modifications having actually occurred, that naturalists can hardly avoid employing language having this plain signification. On my view these terms may be used literally; and the wonderful fact of the jaws, for instance, of a crab retaining numerous characters, which they probably would have retained through inheritance, if they had really been metamorphosed during a long course of descent from true though simple legs, is explained.

Embryology and Development .

This is one of the most important departments of natural history. Herein are included the ordinary metamorphoses of insects, with which every one is familiar. These are generally effected somewhat abruptly by a few stages and in a concealed manner; but the transformations are in reality numerous and graduated. For instance, Sir J. Lubbock has recently shown that a certain ephemerous insect (Chlöeon) during its development moults above twenty times, and each time undergoes a certain amount of change; in such cases