 Reptiles in the traditional knowledge and imaginary of the Nahua / Maseualmej from the Sierra Norte de Puebla (Mexico) 
Snakes rank among the animals which Claude Lévi-Strauss called ‘good to think about’. In this paper, we analyse the representations concerning reptiles and amphibians among the Nahua/Maseualmej who live in the Apulco River valley, in the Sierra Norte de Puebla, Mexico. In these representations, we distinguish three levels: empirical-cognitive, practical and cosmic. Here, we shall explore this third level. Our ethnographic research showed a striking structural continuity between the attributes and functions of some reptiles in contemporary indigenous representations and those linked with gods among the Aztec, at the time of the Spanish Conquest, in spite of the changes in content. For example, one function of Quetzalcoatl (hybrid of bird and snake) that of ‘clearing the way for clouds’ has been taken by the swallow, which ‘sweeps the sky’. Nowadays, under the form of a fantastic snake, kuesalkouat, along with the gecko, ‘calls for the rain’. In a similar way, the feeding functions of Tlakoc and Chicomecoatl are now shared between Aueuejcho and the Thunderbolts, which ‘make the rain to fall’ on the one hand, and the Talokej and the boa, which protect the growth of corn, on the other hand. Globally, our inquiries showed that among today’s Maseualmej, Nature, and particularly the animal kingdom, melts with a Supernature. In the same way, the frontier between human beings and animals is porous and crossed by mytical links as appears when we examine the beliefs related to the ‘double-soul’ (tonal).