12 CLIMATES TIERRAS TEMPLADAS, CALIENTES, FRIAS. 



it is, that throughout the table lands, the geographical position, as 

 far as latitude is concerned, is entirely neutralized by the extreme 

 rarefaction of the atmosphere obtained by ascending through loftier 

 regions. Humboldt graphically declares that climates succeed each 

 other in strata or layers, as we pass from Vera Cruz to the capital, 

 or from the capital, descend to Acapulco or San Bias on the 

 west coast, — beholding in our varied journey, the whole scale of 

 vegetable life. The wild abundance of vegetation on the shore of 

 the Gulf, — its beautiful palms whose stems are wreathed by a 

 myriad of impenetrable parasites which grow with such rank luxu- 

 riance in the hot and humid air of the tropics, — are exchanged, 

 as we begin to rise from the level of the sea, for hardier forest trees. 

 At Jalapa the air is milder, though the vapors from the Gulf which 

 concentrate and condense at about this height on the sides of the 

 mountains, sustain the perpetual freshness of the verdure. Further 

 on, the oak and the orange give place to the fir and pine. Here 

 the rarefied air becomes pure, thin and perfectly transparent ; but 

 as it necessarily lacks moisture, which condenses below this region, 

 the vegetation is neither so luxuriant nor so constantly vigorous. 

 Great plains or basins, spread out in silent and melancholy vistas 

 before the traveller, — many of them, cold, bleak and lonely moors, 

 whose dreary levels sadden the heart of the spectator. The sun 

 which comes down through the cloudless medium of an atmosphere 

 unscreened by the usual curtain of vapor, parches and crisps the 

 thirsty soil, whilst the winds that sweep uninterruptedly over the 

 unbroken expanse, fill the air, during the dry season, with sand and 

 dust. These high barren plains occupy a large portion of the 

 centre of the country between Zacatecas, Durango and Saltillo ; 

 and such is in fact the character of large portions of the whole of 

 Mexico, except when the comparatively level nature of the soil per- 

 mits the small rivulets that filter from the Cordillera through the 

 narrow vallies, to form themselves into rivers which may be used 

 for irrigation. Wherever this is the case nature at once recovers 

 her vio-or under the influence of heat and moisture. 



o 



These physical features, and consequent diversities of tempera- 

 ture, have caused the division of Mexico, as it rises from the two 

 Oceans, into three regions, or superficial strata, which are called, 

 the tierras calientes, or hot lands ; the tierras templadas, or tem- 

 perate lands ; and the tierras frias or cold lands. The tierra 

 caliente covers chiefly that portion of the territory which lies on 

 the borders of the Atlantic and Pacific ; yet it is not confined 

 exclusively to the coast, inasmuch as all those parts of Mexico 

 in which there is heat and moisture enough to produce the fruits 



