It will probably be found that errors of memory are most likely to occur from confusing the direction of the lines which signify blue and red respectively; this may be avoided to some extent by connecting the letters H.B., which distinguish what is perhaps the most used grade of lead-pencil, with the fact to be remembered: Horizontal = Blue. Also the fact that objects on the horizon are blue may assist the memory. [Illustration: FIG. 36.] The furs are as follows: Ermine, it is hardly necessary to say, is white with black spots (Fig. 36). Ermines is black with white spots, and is probably a purely heraldic inversion of ermine. Erminois is ermine with a gold ground instead of white, and Pean, which is inverted erminois, has a black ground spotted with gold. The actual ermine being composed of many small skins sewn together, the black-tipped tails formed a regular powdering of spots. These, however, have from the earliest heraldic times been represented by conventional forms of immense variety, which usually consist of a divided central portion with the addition of three spots above, the latter being sometimes embellished with diverging lines. The conventional version of ermine was even used in costume, being painted on the material which was used by those to whom the wearing of real ermine was forbidden by sumptuary law. It will be observed that the body of the spot has become turned upside down in its transition from the form of the natural tail. [Illustration: FIG. 37.] [Illustration: FIG. 38.] [Illustration: FIG. 39.] By a similar combination of small skins, in this case grey and white, _Vair_ was formed (Fig. 37), and this fur also acquired a generally conventionalized shape, which became, in its late variety, somewhat like a series of the hideous eared shields of the eighteenth century. Vair is understood to be argent and azure in alternate spaces, the blue representing the grey part of the natural fur, and it is only when other tinctures are employed that they need to be mentioned in the blazon. In the latter case the term changes to vairy, or vairé, of such and such tinctures. One of the older forms of vair was made with undulating lines alternating with straight ones (Fig. 38), and is obviously better than the modern form. Another early variety carried the curved lines up to the straight ones, and was drawn somewhat as though the angles of the modern vair were rounded into curves, the result being a pleasant form that is shown in Fig. 39. Vair may be of three tinctures or even more, and instances are mentioned, by Gerard Leigh for example, but such cases are very rare. Potent is a fur similarly built up whose skins are in the shape of crutch-heads, and it is subject to the same colour conditions as vair (Fig. 40). [Illustration: FIG. 40.] [Illustration: FIG. 41.] [Illustration: FIG. 42.]