T.T. Waterman
Calendar symbols of one sort or another occur on a surprising variety of monuments, both of early and late periods. The most important of these monuments for the study of the workings of the calendar system in detail are certain remarkable picturebooks or manuscripts, made on folded strips of deerskin, or on paper made of the fibre of the maguey (Agave americana). These manuscripts are usually spoken of as "codices." Only a few of these native manuscripts survived the introduction of European civilization into America. Those which were preserved were taken to Europe as curiosities, and often preserved through mere luck. The ones still extant have received a great deal of attention since the early part of the last century. All but a few of the originals are still in Europe, and are at the present time considered priceless.
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