454 THE INSCRIPTIONS AT COPAN. 
burned, more and more of its humus soil is destroyed by the fire, and it 
requires longer and longer intervals of time for the woody growth upon 
which such a system of agriculture depends to return. After each successive 
burning more and more coarse grass grows up, and fewer and fewer trees 
and bushes, until finally nothing but coarse grass will grow and agriculture 
as practiced by the Maya is no longer possible. Cook describes this process 
in the highlands of Guatemala as follows: 
“The usual system of corn culture involves the repeated burning off of the 
weedy growth and a resulting exposure of the soil. ‘This causes a gradual deterior- 
ation of the crops of corn and a slower renewal of the woody vegetation. New 
clearings in the forest are soon covered again with bushes, and can be cut, burned, 
and planted again within a year or two. With each cutting the interval has to be 
lengthened, until finally the land becomes thoroughly occupied by coarse grasses 
which are not killed by fire. The Indians can then make no further use of the land 
for agricultural purposes.” 
This method of agriculture, he goes on to say, has been carried in the 
highlands of Guatemala, at San Pedro Carcha near Coban, for example, to 
the point where the barren grassy zone is of such an extent that the Indians 
plant their mi/pas in the Cajabon district, 80 kilometers distant, and carry 
the crop home on their backs. 
As applied to the Old Empire, such a system of agriculture would have 
required a vast extent of territory to have supported the large population 
which formerly occupied this region, and if this hypothesis is correct, per- 
haps we are to imagine the ancient inhabitants of Copan, Tikal, and the 
other southern Maya cities as being driven farther and farther from their 
homes in order to find suitable forested regions in which to make the clear- 
ings for their mi/pas. 
Such a system of agriculture, if pursued long enough, would eventually 
have exhausted all the available forest lands within practicable carrying 
distances of the centers of population, and with grassy savannas stretching 
far out on every side replacing formerly forested regions; as Cook says: 
“civilization is at an end when an agricultural country ceases to be adapted 
to agriculture.” 
This hypothesis appeals to the writer personally more than any of the 
others described. ‘To begin with, it best explains the progressive abandon- 
ment of the Old Empire cities, which we have seen took place not all at once, 
but scattered over a period of about a century. This replacing of the forests 
by grassy savannas, and the end of cultivability so far as the Maya 
agricultural methods were concerned, must have come about gradually, 
reaching really acute stages at the different cities at different times, depend- 
ing upon such variable factors as their relative sizes and ages, and the 
general fertility of their surrounding regions. 
Thus the point at which complete abandonment and migration else- 
where came to be generally recognized as the only remaining solution for 
1 Cook, 1909, p. II. 
