In 1325, as we learn from their old records, a great change took place in the condition of the Aztecs. Some of the tribe saw on a reedy island on the lake a splendid eagle perched on one of the cactus-plants with which the region abounds. His wings were outstretched toward the rising sun, and he held a writhing serpent in his beak. The old oracle of the tribe was consulted again. He decided that this was a token that the gods were smiling on the Aztecs and wished to point out this place as a site on which they ought to build a city. This was begun by sinking piles in the water. On these they first built little thatched cabins, with walls woven out of the reeds they found growing on the lake-shore, and plastered with mud. They called the place Tenochtitlan (or "Stone-cactus City"), either because of this circumstance or because one of their leading chiefs was called Tenoch ("Stone Cactus"). The Aztec capital—for such it became—was afterward named Mexico, after Mexitli, one of their gods. Year after year, as the tribe pushed out and increased in numbers and wealth, the islands on which they lived were linked together and to the mainland by strong causeways of stone. The place Mexitli became impregnable to Indian warfare. They continued by means of their long dykes not only to join the island to the mainland, but so to pen up the waters flowing into the lake as to surround the city with deep water, and thus defend it in case of a siege. At intervals sluices were cut through the causeways, over which openings bridges were thrown that could be taken up in time of war.
It is probable that for many years the tribe owned no other land than that on which their city stood. It was divided into four quarters, or calpulli, each having its own chief and temple, council-house, and other public
