Guatemala Forests. 397 
rarifies the air, cools it and reduces its capacity for holding aque- 
ous vapor, and results in condensation and copious rainfall. It is. 
like squeezing a saturated sponge. When the culminating sum- 
mits of the Cuilco Mountains, the Sierra Madre, Sierra de Chania 
and Sierra de las Minas are reached, the last squeeze is given to- 
the sponge and the winds cross over to the interior table lands, 
dry. This causes a dry belt along the leeside of these mountains. 
extending from Facaná and Cuilco in the northwest by way of 
Huchuetenango, Chiantla, Rabinal and Salamá to Zacapa and 
Chiquimula in the southeast. As the air descends from summits of 
12,000 to 8000 feet high to the interior plains of only 7000 to 1000: 
feet elevation, it expands again and takes up moisture from the- 
soil, dessicating the climate further and making the dry belt a very 
marked feature of the country. One writer even calls the low hot 
plains of Zacapa a “ desert.” The pine is very common in this belt 
at all elevations in favorable situations, and also the oak above 3000 
feet. In the driest parts and ‘in rocky places the character of the 
vegetation is special and peculiar. Cacti, thorny mimose, and 
many kinds of thorny and prickly shrubs abound. As the air 
rises again, or the higher currents reach the summits of the moun- 
tains facing the Pacific, the sponge, replenished from evaporation 
over the dry belt, is squeezed again, causing mists and copious. 
rain, and limiting the dry belt to the south and southwest. 
The Pacific slope has a moist, tropical climate of its own from: 
the influence of the ocean winds, and is independent of moisture 
brought from the east. 
Finally, I have to mention a third great cause affecting the: 
forests of Guatemala; the influence of the ancient people who 
cleared nearly or quite all the ground that is cultivated or pastured) 
to this day, and much more besides that has become overgrown: 
again with forests. The general proposition will hold that all the 
clearings of the ancient people in the dry belt, and most of them in its 
semi-dry borders, have remained cleared, whether cultivated and 
pastured or not, excepting grass, weeds and shrubbery scattered 
and in clumps. But to this general rule there is a remarkable 
exception. In favorable situations, as to moisture and depth of 
soil, pine forests, with some oak, cover the ancient fields and 
village sites. In such clean open pine forests, terrace walls, ruined: 
structures, and whole villages are found, but all very ruined andi 
ancient-looking. 
