_The caduceus._--This is one of the interesting symbols of antiquity. It appears in many phases and is an excellent illustration of the migration of symbols. Its classic type held in the hand of Mercury and used to-day as a symbol of the healing art--a winged rod round which two serpents are symmetrically entwined--is due to the mythographers of later times, and is very remote from its primitive form. In the Homeric hymn it is called "the golden rod, three-petaled of happiness and wealth," which Phoebus gave to the youthful Hermes, but on early Greek monuments the three leaves are represented by a disk surmounted by an incomplete circle. In this shape it constantly appears on Phenician monuments; and at Carthage, where it seems to have been essentially a solar emblem, it is nearly always associated with the sacred cone. It is found on Hittite monuments, where it assumes the form of a globe surmounted by horns. Numerous origins and manifold antecedents have been attributed to it, such as an equivalent of the thunderbolt, a form of the sacred tree, or a combination of the solar globe with the lunar crescent. Some examples seem to indicate a transition from the sacred tree surmounted by the solar disk, to the form of the caduceus of the Hittites. Our author believes it was employed originally as a religious or military standard or flag, and that it was gradually modified by coming in contact with other symbols. Some Assyrian bas-reliefs display a military standard, sometimes consisting of a large ring placed upon a staff with two loose bandelets attached, sometimes of a winged globe similarly disposed. This Assyrian military standard may be the prototype of the labarum, which Constantine, after his conversion to Christianity, chose for his own standard, and which might equally well have been claimed by the sun worshipers. Under its latest transformation in Greece, a winged rod with two serpents twined round it, it has come down to our own times representing two of the functions of Hermes, more than ever in vogue among men, industry and commerce. It has survived in India under the form of two serpents entwined, probably introduced in the track of Alexander the Great. It was also met with in that country in earlier times in its simpler form, a disk surmounted by a crescent, resembling our astronomical sign for the planet Mercury. This earliest type of the caduceus, a disk surmounted by a crescent, appears at a remote date in India, and seems to have been confounded with the trisula.