The central boss, at once an appropriate ornament of an early shield, and an important addition to its defensive qualities, when extended in the form of decorative metal-work, would readily suggest a variety of heraldic figures, and amongst others several beautiful modifications of a simple cruciform device which it might be made to assume. The figure called an escarbuncle, No. 19, is simply a shield-boss developed into decorative structural metal-work. This figure appears in the Temple Church, London, upon the shield of an Effigy, which Mr. J. Gough Nichols has shown to have been incorrectly attributed to Geoffrey de Mandeville, Earl of Essex. [Illustration: No. 19.--The Escarbuncle.] The greater number of the earliest devices that appear in English Heraldry were adopted for the express purpose of their having some _allusive association_, through a similarity of sound in their own names or descriptions with the names and titles or the territories of certain persons, dignities, and places. In exact accordance with the principles and aim of primitive mediæval Heraldry, and in perfect harmony with the sentiments and requirements of the age in which it grew up into a science, devices of this kind addressed themselves in very plain and expressive language to the men of their own era. In them they saw the kind of symbolical writing that they could remember, as well as understand. They also evidently liked the quaint style of suggestiveness that was a characteristic of these allusive devices: and, it is more than probable that there frequently lurked in them a humorous significance, which by no means tended to detract from their popularity. Devices of this same order have never ceased to be in favour with Heralds and lovers of Heraldry. They were used in the sixteenth century at least as commonly as in the thirteenth; but, as would be expected, in the later period they often became complicated, far-fetched, and extravagant. This allusive quality, distinguished in English Heraldry as “_canting_,” has commonly been misunderstood, and therefore incorrectly estimated, by modern writers, who have supposed it to be a fantastic conceit of the Heralds of a degenerate age. By writers such as these, accordingly, all “_canting arms_” (by French Heralds called “_armes parlantes_”) have been absurdly assigned to a separate class, in their estimation having an inferior heraldic grade.