Bernal Diaz, who was with the expedition and saw this man when he arrived, relates that when Aguilar came before the presence of Cortes he cowered down according to the manner of Indian slaves. Aguilar stated that only he and another Spaniard named Gonzalo Guerrero, were then alive. Most of his companions had been sacrificed to the gods, but some had died, and two women who were with them had perished from misery and the severity of the labour of grinding maize. Guerrero had married an Indian woman and followed the native customs. He had been tattoed, his ears were pierced and his lips were turned down.[106] Aguilar had become acquainted with the Maya language, and was afterwards employed by Cortes as an interpreter. Guerrero remained in Yucatan with the Indians. Upon a review of the facts ascertained by the conquerors in the sixteenth century in Mexico and Guatemala, and by the Franciscan and Dominican missionaries in Yucatan and Chiapas, together with the researches made since that time by archæologists and explorers, it appears to be possible to form certain conclusions. The architectural and mechanical knowledge, and the advance towards writing characters, forming calendars and reckoning time by astronomical observations must have been reached within a period of less than four centuries. It is therefore probable that the priests of the Toltecs became acquainted with their arts and sciences not long after they had left North America and had migrated to the regions around Téotihuacan in the direction of the shores of the Gulf of Mexico. In what manner and under what circumstances their knowledge was obtained, is a problem which requires to be given a careful investigation. • • • • • In an Aztec or Toltec manuscript which forms part of the collection of ancient Mexican codices placed in the library of the Vatican, there is a representation of a cacique making an offering to a rattlesnake. The manner of propitiation resembles the methods of sacrificing to this Manito which were followed by the Dakotas (see p. 170). The head dress of the cacique which consists of plumed feathers is similar to that worn by the chiefs of that race, and is placed in the same position as the feathers of Rocky Bear (illustration, chapter viii). The rattlesnake appears to have been the Totem of the Toltecs and is the chief emblem at Uxmal and Chichen Itza. It is thought that a serpent is represented upon the central stone of the tablet of the cross at Palenque and as the god to whom the temple is dedicated was named Bird-Serpent (Quetzal-Coatl), it is probable that the sculptors delineated the symbol in a manner that was intelligible to the Quichés.