The family-likeness that exists among the stone tools and weapons found in so many parts of the world is very remarkable. The flint-arrows of North America, such as Mr. Longfellow’s arrow-maker used to work at in the land of the Dacotahs, and which, in the wild northern states of Mexico, the Apaches and Comanches use to this day, might be easily mistaken for the weapons of our British ancestors, dug up on the banks of the Thames. It is true that the finish of the Mexican obsidian implements far exceeds that of the chipped flint and agate weapons of Scandinavia, and still more those of England, Switzerland, and Italy, where they are dug up in such quantities, in deposits of alluvial soil, and in bone-caves in the limestone rocks. But this higher finish we may attribute partly to the superiority of the material; for the Mexicans also used flint to some extent, and their flint weapons are as hard to distinguish by inspection as those from other parts of the world. We may reasonably suppose, moreover, that the skill of the Mexican artificer increased when he found a better material than flint to work upon. Be this as it may, an inspection of any good collection of such articles shows the much higher finish of the obsidian implements than of those of flint, agate, and rock-crystal. They say there is an ingenious artist who makes flint arrow-heads and stone axes for the benefit of English antiquarians, and earns good profits by it: I should like to give him an order for ribbed obsidian razors and spear-heads; I don’t think he would make much of them. [Illustration: Aztec Knife of Chalcedony, mounted on a wooden handle, which is shaped like a human figure with its face appearing through an eagle-head mask, and has been inlaid with mosaic work of malachite, shell, and turquoise. Length 12½ inches.[12]] [12] The unique Knife figured at page 101 and two masks incrusted with a similar mosaic work (of turquoise and obsidian) are in Mr. Christy’s collection; and a mask and head of similar workmanship are in the collection at Copenhagen. These are the only known examples of this advanced style of Aztec art. The whole once belonged probably to one set, brought to Europe soon after the Conquest of Mexico. The two at Copenhagen were obtained at a convent in Rome; and, of the other three, two were for a long period in a collection at Florence, and the other was obtained at Bruges, where it was most probably brought by the Spaniards during their rule in the Low Countries. The wonderful similarity of character among the stone weapons found in different parts of the world has often been used by ethnologists as a means of supporting the theory that this and other arts were carried over the world by tribes migrating from one common centre of creation of the human species. The argument has not much weight, and a larger view of the subject quite supersedes it.