You know there is a proverb which says, "Those who live in glass houses should not throw stones;" that is generally one of the first proverbs we learn, and _always_ the very first one we forget. I am afraid that those old Aztecs lived in _rather_ a glass house, for _they_ had a plan of cutting people open, whilst they were still alive, and tearing their hearts out. Horrible! was it not? But they did not _burn_ people; so, when they saw the Spaniards doing so, they were shocked at them. As for the Spaniards, _they_ were shocked at the Aztecs doing this other thing, for _that_ had never been _their_ custom. So the Aztecs and the Spaniards were shocked at each other. People are very easily shocked at each other, but they are not nearly so easily shocked at themselves. Now I come to think of it, I never remember hearing any one say, "I am _shocked_ at myself!" And yet it would often be a quite sensible remark. But what I wanted to tell you about these old Aztecs, who lived in Mexico all that time ago, was that, when the Spaniards came there, they were ruled over by a great king named Montezuma, and this king, amongst many other wonderful things, had a great place, where he kept all the different kinds of birds that were found in his country. A place like that is called an aviary, and you may be quite sure that the beautiful Trogon or Quezal was one of the birds in King Montezuma's aviary, for it was more highly thought of than any other bird in the country. Let us hope that all the birds in this aviary had nice, large places to be in, with trees, and flowers, and everything that they wanted; and, as it was a king's aviary, I daresay they had.