218 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 93 



For the first half of our journey the land was low and marshy, with 

 connecting channels between the larger streams. Far to the south we 

 could see the outline of the Sierra de Tuxtla, while to the north, dimly, 

 appeared the great bulk of Orizaba. At La Candera the land became 

 higher, and extensive forest of fair-sized trees appeared. After five 

 hours' travel we reached the head of navigation at Boca San Miguel 

 (pi. 26, fig. 2). Tide influence in the stream extended to this point. 

 The stream here had fairly high banks with the elevation at the little 

 palm-thatch houses that marked the place at about 40 feet above sea 

 level. Here our outfit was transferred to an oxcart, while we rode 

 mules for the 2-hour journey to camp, a mile beyond the village of 

 Tres Zapotes. 



The location was as ideal for the biologist as for the archeologist. 

 The three palm-thatch houses of the camp were placed on slightly 

 elevated ground, with the mounds marking the activities of the ancient 

 inhabitants spread on all sides. The land is slightly undulating and 

 is cut by the winding course of the Arroyo Hueyapa, a stream of clear 

 water that comes down to the river at the Boca. From our houses we 

 looked out across the open pastures of a small savanna to the Cerro de 

 Tuxtla, with the low slopes of Cerro Prieto and the higher Volcan 

 San Martin in the distance. Dense jungle began beside us and ex- 

 tended for miles, except where considerable tracts had been cleared 

 and planted in corn by the villagers. These milpas are cultivated 

 for four or five years until the tough-rooted grass finally gets the 

 upper hand. They are then abandoned (pi. 27, fig. 1) and new clear- 

 ings are made in the adjacent jungle. The old fields produce heavy 

 stands of grass that are burned somewhat casually in the dry season 

 but gradually grow up in bushes, which little by little form thickets 

 and in the end are covered by second-growth forest. This ecological 

 cycle, judged from the archeological evidence, has continued here for 

 centuries, possibly for 2,000 years or more, with steady shift and 

 change of plant and animal life in accommodation to the agricultural 

 activities of man. The general elevation is less than 200 feet above 

 sea level, with the land rising in rolling hills toward the Sierra de 

 Tuxtla and becoming lower toward Hueyapa and the river. 



Rainfall is heavy, with a limited dry season beginning in March 

 and extending through the month of May. During our stay cold 

 storms of rain and wind (nortes) swept down periodically from the 

 north until the beginning of the dry season, flooding the lowlands 

 with water, with the thermometer dropping regularly to 50° F. Even 

 in the heat of the dry season the nights usually were cool. 



Near Tres Zapotes village there are several small lakes and marshy 

 channels (pi. 28, fig. 2). Laguna Larga begins adjacent to the houses 

 and extends for some distance behind a low ridge, beyond which is 



