[2] "We have seen many instances of such opposed animals and birds on the metal-work and carving of the thirteenth century, and there is no doubt that the design is much older than Mohammedan times, and goes back to the productions of the old artists of Mesopotamia and Persia. We read in Quintus Curtius of robes worn by Persian satraps, adorned with birds beak to beak--_aurei accipitres veluti rostri in se irruerunt pallam adornabant_. Plautus mentions Alexandrian carpets ornamented with beasts: _Alexandrina belluata conchyliata tapetia_. There is indeed reason to believe that the notion of such pairs of birds or beasts may have originated with the weavers of ancient Persia, and have been borrowed from them by the engravers of metal-work; for the advantage of such double figures would be specially obvious to a weaver. The symmetrical repetition of the figure of the bird or animal, reversed, saved both labour and elaboration of the loom. The old weavers, not yet masters of mechanical improvements, were obliged to work their warp up and down by means of strings, and the larger the design the more numerous became these strings and the more complicated the loom. Hence, to be able to repeat the pattern in reverse was a considerable economy of labour, and could be effected very simply on a loom constructed to work _à pointe et à reverse_. Examples of such repetitions of patterns, especially of symmetrical pairs of animals within circles, are common in Byzantine and Sassanian woven work, and the Saracens followed these models."--Stanley Lane-Poole, _The Art of the Saracens in Egypt_, p. 288.