This is a very broad topic and its treatment is quite complex. The time necessary to complete a systematic search of the pertinent literature, which is very rich and very dispersed, was lacking to us. For these reasons, we do not hope to offer here more than some considerations based on certain cases which can be considered as symptomatic.
The area which we shall study extends in area from New Mexico to Chiapas and in time from the conquest of Tenochtitlan completed in 1521 to that of Tamaulipas, completed in 1755. Moreover, we shall make some reference in passing to the actual state of Christianity among certain groups of indigenes.