Some of the ordinary rock pictures may have been carved for simple amusement, but the majority were made with a purpose, and this was usually the communication or record of an idea. The Amerind records may be divided into two and perhaps three general classes: first, the mnemonic; second, the ideographic; and, third, the phonetic. Brinton suggests for the writings of the Aztecs, which were partly ideographic and partly phonetic, the term _ikonomatic_,[47] and used it in his own works. The ideographic class are those which represent an idea, as a man striking another, like the accompanying illustration from the autobiography of Running Antelope, who thus records his killing of two Arikarees. The mnemonic class do not represent an idea, but simply are memory helps, like a string tied around one’s finger, a good example being any numeral, say the figure “9.” The phonetic class represent sounds, like the letters of our alphabet, say the letter “e.” It is believed that the Maya writings were largely phonetic, but the phonetic quality is not well established. [Illustration: PETROGLYPHS ON PAINT ROCK, NORTH CAROLINA] It is supposed that the mnemonic symbols originated in sign-language. One of the most striking examples of the universality of the sign-language is the case, cited by Mallery, of a professor in a deaf-mute college, who, visiting several wild tribes, was able to communicate freely with them though he knew nothing of their spoken languages. It was a natural thing that races should attempt to record these signs, and some early hieroglyphs in Egyptian can clearly be traced to them. These same efforts occurred amongst the Amerind stocks in varying degree. Picture-writing, the world over, as well as particularly in North America, probably grew out of sign-language, giving, as the first stage in the development, sign-language, second pictographs, third alphabet. These merge into each other, as there was not a series of jumps, but a slow and gradual progression. Many pictographs are merely representations of natural objects and had no special significance, others were guide marks to springs, others recorded visits to certain localities. Mallery states a particularly interesting fact, that within “each particular system ... every Indian draws in precisely the same manner.” Therefore, if a perfect understanding of each tribal system is obtained, the various rock markings and other pictographs can be classified. Sometimes frauds[48] have been attempted by white men, one well-known case being where an Illinois blacksmith copied on six copper plates designs from a Chinese tea-box, and then claimed that the plates had been found in a mound. Recently a most ingenious counterfeiter of stone implements was discovered in Dane County, Wis. He had been selling the spurious implements for years. They are usually of bizarre patterns.[49] Bandelier says that “it is certain that some of them [pictographs in