But apart from the foregoing reasons, it must be remembered that many of the earliest monuments of typographic art appeared not only without the name of the printer but also without that of the locality in which they were printed. Although in such cases various extraneous circumstances have enabled bibliographers to “place” these books, the Mark of the printer has almost invariably been the chief aid in this direction. The Psalter of 1457 is the first book which has the name of the place where it was printed, besides that of the printers as well as the date of the year in which it was executed. But for a long time after that date books appeared without one or the other of these attributes, and sometimes without either, so that the importance of the Printer’s Mark holds good. A very natural question now suggests itself, “Who invented these Marks?” Laire, “Index Librorum” (Sæc. xv.), ii. 146, in speaking of a Greek Psalter says: “_Habet signaturas, registrum ac custodes, sed non numerantur folia. Litteræ principales ligno incisæ sunt, sicut et in principio cujuslibet psalmi viticulæ quæ gallicé _vignettes_ appellantur, quarum usum primus excogitavit Aldus._” The volume here described was printed about 1495, and the invention therefore has been very generally attributed to Aldus. That this is not so will be shown in the next chapter. We shall confine ourselves for the present to some of the various points which appear to be material to a proper understanding of the subject. One of the most important and interesting phases in connection with Printers’ Marks is undoubtedly the _motif_ of the pictorial embellishment. Both the precise origin and the object of many Marks are now lost to us, and many others are only explained after a thorough study of the life of the particular printer or the nature of the books which he generally printed or published. The majority, however, carry their own _prima facie_ explanations. The number of “punning” devices is very large, and nearly every one has a character peculiarly its own. Their antiquity is proved by the fact that before the beginning of the fifteenth century, a picture of St. Anthony was boldly, not to say irreverently, used by Antoine Caillaut, Paris. A long series of punning devices occur in the books printed by or for the fifteenth century publishers, one of the most striking and successful is that of Michel le Noir, whose shield carries his initials, surmounted by the head of a negress and sometimes supported by canting figures in full. This Mark, with variations, was also employed by Philippe and Guillaume le Noir, the work of the three men covering a period of nearly 100 years. The device of Gilles or Gillet Couteau, Paris, 1492, is apparently a double pun, first on his Christian name, the transition from which to _œillet_ being easy and explaining the presence of a pink in flower, and secondly on his surname by the three open knives, in one of which the end of the blade is broken.