The simple catalogue of these names, indicating the sites of ancient civilization in the midst of what is at present almost an unexplored wilderness and covering so wide a field of observation, will satisfy the reader that it is impossible to condense a satisfactory review of these architectural remains within the space that we are enabled to appropriate to antiquarian researches. The ruins of Palenque in Chiapas, and of Uxmal and Chichen in Yucatan, are, perhaps, the most wonderful of all that have been explored hitherto in this lonely region; and, while we regret that our duty to the living present will not permit us to dwell longer on the curious past, we shall, nevertheless pause, occasionally, as we pass through the Mexican States, to notice those remains which have either been visited by us personally, or are not described in books as accessible to all classes of enquirers and students as those of Messrs. Stephens, Catherwood and Norman. Mr. Stephens believes, after full investigation, that these towns and cities were occupied by the original builders and their descendants at the period of the Spanish conquest, and our own opinion entirely coincides with his reasoning and judgment. Those who desire a complete and conclusive illustration of this branch of the subject will find an excellent argument thereon in both of his publications.[47] In the first volume of this work we have given an account of the Mexican or Aztec Calendar; and the proximate identity of the Yucatese or Mayan and Aztec Calendar led Mr. Stephens to the conclusion that both nations had a common origin. This argument is also important in considering the period of the occupation of the Chiapan and Yucatese edifices, inasmuch as we know that the Aztecs of Montezuma's period used the Calendar which we have already illustrated and described. YUCATAN CALENDAR. "Our knowledge of the Yucatan Calendar," says Mr. Gallatin,[48] "is derived exclusively from the communications made by Don J. P. Perez to Mr. John L. Stephens, and inserted in the appendix to the first volume of this gentleman's Travels in Yucatan. It is substantially the same with that of the Mexicans, though differing in some important particulars.