The New World is rich in ancient monuments often adorned with symbolic devices, but older than these are the pictographs covering erratic blocks and cliff escarpments from Guiana to Nova Scotia, and westward to the Rockies. Some are incised in the hard stone to a depth of half an inch; others are traced in broad lines of red ochre or other colour, their weather-worn state witnessing to a high antiquity. Their purpose is often not easy to explain, but we know that therein lie the germs whence alphabets sprung. One picture (fig. 6_a_) on the face of a rock on the shore of Lake Superior, copied and interpreted by Schoolcraft, records an expedition across the lake, led by Myeengun, or "Wolf," a noted Indian chief. The crew of each canoe is denoted by a series of upright strokes, Myeengun's chief ally, Kishkemanusee, the "Kingfisher," being in the first canoe. The arch with three circles (three suns under heaven) shows that the voyage took three days. The tortoise (a frequent symbol of "land" in North American picture-writing) seems to indicate the arrival of the expedition, while the picture of the mounted chief evidences that the event took place after the introduction of horses into Canada. Some of the examples, less easy to explain, represent the migration of tribes; some, like the sculptured eagle near the borders of Quauhuahuac ("the place near the eagle") are symbolic boundary-marks; while others are direction-marks. Some have life-size human figures, rayed or horned; one engraved on a rock overlooking the Big Harpeth, in Tennessee, depicts a sun visible four miles off. Doubtless a large number of this class (fig. 6_b_) are merely the outcome of that rude artistic fancy of man which, as has been seen, has had continuous expression from prehistoric times. [Illustration: Fig. 6_b_.--Various Types of the Human Form] CHAPTER III MEMORY-AIDS AND PICTURE-WRITING