The most interesting mediaeval example of the classical form of manuscript made up of several leaves of waxed tablets was found a few years ago in a blocked-up recess in the old wooden church at Hopperstad in Norway. It was enclosed in a casket of wood covered with leather, and thus it still remains in a very perfect state of preservation; it is now in the University Museum at Christiania. The book consists of six tablets of box-wood, coated with wax within the usual raised margin, and hinged with leather thongs. The outer leaves are decorated on the back with carving mixed with inlay of different coloured woods. _Bestiary._ The manuscript itself which is written on the wax is a _Bestiary_, dating, as its style shows, from the latter part of the thirteenth century, though the book itself is probably older. It contains lists of animals in Latin with a Norwegian translation, and it is copiously illustrated with drawings of scenes from agricultural and domestic life, executed in fine outline on the wax with a sharply pointed stilus. In every detail, except of course in the character of the writing and drawings, this book exactly resembles an ancient Greek or Roman many-leaved wooden book, [Greek: polyptychon], a very striking example of the unaltered survival of ancient methods for an extraordinarily long period. _Ivory tablets._ During the mediaeval period, sets of ivory tablets hinged together were frequently made for devotional purposes. This form of manuscript has no layer of wax, but the writing is executed with a pen on the thin smooth leaf of ivory. Each leaf has its margin raised, like the ancient _pugillares_, to prevent the two adjacent surfaces from rubbing together. These ivory tablets usually contain a set of short prayers, and they are frequently illustrated with painted miniatures of sacred subjects exactly like those in the vellum manuscripts of the same date. _Tablet with eight leaves._ The South Kensington Museum possesses a very beautiful example of these ivory books; it is of Northern French workmanship dating from about the middle of the fourteenth century. It consists of eight leaves of ivory, measuring 4-1/8 inches by 2-3/8 inches in width. The six inner pages are extremely thin, no thicker than stout paper, and have paintings on both sides, the two covers are of thicker substance, about a quarter of an inch, and are decorated on the outside with beautiful carved reliefs. This remarkable work of art has on the inner leaves fourteen very delicately executed miniatures of sacred subjects, single figures of Saints and scenes from Christ's Passion, painted in gold and colours in the finest style of French fourteenth century art, evidently executed by some very skilful illuminator. _Ivory diptychs._