In his studies of the Cuzco Basin Professor Gregory came to the conclusion that the Ayahuaycco gravel banks might have been repeatedly buried and reëxcavated many times during the past few centuries. He found evidence indicating periodic destruction and rebuilding of some gravel terraces, "even within the past one hundred years." Accordingly there was no longer any necessity to ascribe great antiquity to the bones or the wall which we found in the Ayahuaycco quebrada. Although the "Cuzco gravels are believed to have reached their greatest extent and thickness in late Pleistocene times," more recent deposits have, however, been superimposed on top and alongside of them. "Surface wash from the bordering slopes, controlled in amount and character by climatic changes, has probably been accumulating continuously since glacial times, and has greatly increased since human occupation began." "Geologic data do not require more than a few hundreds of years as the age of the human remains found in the Cuzco gravels." But how about the "bison"? Soon after his arrival in Cuzco, Dr. Eaton examined the first ribs of carcasses of beef animals offered for sale in the public markets. He immediately became convinced that the "bison" was a Peruvian domestic ox. "Under the life-conditions prevailing in this part of the Andes, and possibly in correlation with the increased action of the respiratory muscles in a rarefied air, domestic cattle occasionally develop first ribs, closely approaching the form observed in bison." Such was the sad end of the "bison" and the "Cuzco man," who at one time I thought might be forty thousand years old, and now believe to have been two hundred years old, perhaps. The word Ayahuaycco in Quichua means "the valley of dead bodies" or "dead man's gulch." There is a story that it was used as a burial place for plague victims in Cuzco, not more than three generations ago! CHAPTER VIII The Oldest City in South America Cuzco, the oldest city in South America, has changed completely since Squier's visit. In fact it has altered considerably since my own first impressions of it were published in "Across South America." To be sure, there are still the evidences of antiquity to be seen on every side; on the other hand there are corresponding evidences of advancement. Telephones, electric lights, street cars, and the "movies" have come to stay. The streets are cleaner. If the modern traveler finds fault with some of the conditions he encounters he must remember that many of the achievements of the people of ancient Cuzco are not yet duplicated in his own country nor have they ever been equaled in any other part of the world. And modern Cuzco is steadily progressing. The great square in front of the cathedral was completely metamorphosed by Prefect Nuñez in 1911; concrete walks and beds of bright flowers have replaced the market and the old cobblestone paving and made the plaza a favorite promenade of the citizens on pleasant evenings.