192 MEXICO AND CENTRAL AMERICA 
the reptile tails refers to the first year of the present sun, 
but according to others this is the year 1479 in which 
the sculpture was set up. Unfortunately, we have no 
record of this event. The fifth sun will end with the 
day 4 Olin, that is expressed in the central symbol 
already described. For this reason a fast was held 
on each recurrence of this day. Outside of the Olin 
symbol but between its arms are four hieroglyphs of 
uncertain meaning. Next to this area dealing with 
the great ages of the world comes a band of the twenty 
day signs of the Aztecan month. Outside of this band 
are several others which probably represent in a con- 
ventionalized manner the rays of the sun and the 
turquoise and eagle feathers with which the sun disk 
was believed to be decorated. Finally, outside of all, 
are two plumed monsters meeting face to face at the 
bottom of the disk. In each reptile face is seen a 
human face in profile. These reptiles are probably to 
be identified as the Xuihcoatl or Fire Serpents. 
Stone of Tizoc. The Sacrificial Stone or Stone of 
Tizoc is believed to have been carved by order of Tizoc, 
the war chief who ruled from 1482-1486, as a memorial 
offering to Mexican arms on the completion of the great 
temple to the Mexican God of War. The stone was a 
quauhaxicalli, or “eagle bowl.”’ This name was given 
to large bowls which were used to hold the blood and 
the heart of human victims sacrificed to the gods. The 
same name was extended to the large drum-shaped 
stone, under consideration, which has a pit in the center 
and a sort of canal running from the center to one side 
which may have been intended to drain off the blood. 
Human sacrifice actually took place on this stone but 
it is pretty certain that it was not one of the temalacatl 
or “gladiator stones” on which were staged mortal 
