SUMMARY—ARCHAEOLOGICAL PERIOD (500-1100 A.D.) 
Granary Type Indian Group Distribution 
1. Subterranean Tarahumara Sonora and 
Chihuahua 
2, Niches of caves Tarahumara’ Son. and Chih. 
3. Rectangular and cylindrical, stone Tarahumara_ Son. and Chih. 
and mortar 
. Wattle and clay daub Tarahumara’ Son. and Chih. 
. Vasiform, coiled grass and clay daub T'arahumara’ Son. and Chih. 
OQ oO 
. Clay jars Teotihuacan San Juan Teo- 
tihuacan, Mex. 
IV. Pre-ConavEst PEriop (1100-1518 A.D.) 
For a knowledge of the cultures found in Mexico at 
the time of the Conquest, two extensive sources of  in- 
formation are available: a) the Codicis, and b) the writ- 
ings of men who lived in Mexico during the few decades 
following the Conquest. It seems reasonable to assume 
that these historical documents refer to cultural traits of 
a well-established pattern which remained unchanged for 
some time after the Conquest. For this reason, this in- 
formation is interpreted as a reflection of conditions ex- 
isting previous to the Conquest. 
The Codicis are a form of pictorial writing used by the 
Mexican tribes to record such information as tribal his- 
tory, rights to land ownership, commercial transactions 
and tribute lists. The pictorial technique varied widely 
probably as the result of a constant development from 
pure pictorial representation to a semi-phonetic writing. 
Of the Codicis which escaped destruction, the most im- 
portant ones to our problem are the Codex Mendoza, 
the Historia Chichimeca, the Yanhuitlan Codex, the 
Codex 'Troano-Cortesiano and the Lienzo de Tlaxcala. 
The information gleaned from these sources may be 
divided into two categories: a) one referring to the stor- 
age structures used by the rulers, and b) the other re- 
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