The Plan of the Earth and its Causes. — Gregory. 109 
mountain system, connected into a continuous line by a moun- 
tain axis running north and south across Central America. 
But that axial mountain chain in Central America is a myth. 
Central America is traversed by a series of ridges which 
run east and west, and not north and south.* The watershed, 
it is true, runs along the Pacific border, but that is due to a 
movement later than the mountain ridges which are thus trun- 
cated. The continuation of the Andes is in the mountains of 
Venezuela, not in North America or the Sierra Nevada. The 
Andes and the mountain system of the western states of 
FIG. 3. — THE MOUNTAIN SYSTEM OF CENTRAL AMERICA, a, VOL- 
CANIC CHAIN OF HEREDIA; b, SIERRA CANDELLA; C, CORDIL- 
LERA DE DOTA; d, SIERRA CHIRIQUI ; €, SIERRA VERAGUA ; /, 
CORDILLERA DE SAN BLAS ; g, VOLCANIC CHAIN OF ALAJUELA. 
America are essentially distinct; they differ in every import- 
ant respect, geological structure, geographical characters, and 
dates of formation. Any theory which assigns the Andes and 
*B.ff. the Sierra Candela, Cordillera de Dota, Sierra Chiriqui, Sierra 
Veragua, Cordillera de San Bias, etc. 
