The earliest cultural remains come from zone D and 
are considered to belong to the Lerma Phase. At present, 
these cannot be accurately dated. The presence of thin 
fragments of deer bones, numerous large, double-pointed, 
thick projectile points and a wide variety of skin-scraping, 
chopping and cutting tools suggest that the subsistence 
of the first occupants of a Perra Cave was based largely 
on hunting. 
The second complex of artifacts, from zone B, are con- 
sidered to belong to the La Perra Phase. Other compo- 
nents of this phase were exhumed in Nogales Cave, 12 
miles down the canyon from La Perra Cave, and in Cueva 
Humada in the southern Sierra de Tamaulipas. Alto- 
gether five sites belonging to this phase were found dur- 
ing the reconnaissance. The La Perra Phase appears to 
be related to a series of archaeological manifestations 
which range spatially from southern Texas to San Luis 
Potosi, Mexico. One of these from Falcon Dam in Texas, 
has been dated as 4650 years old, another from Tamau- 
lipas as 3945 years old. 
Vegetal remains from the lower part of zone B have 
been dated by radiocarbon determination at 4445180 
years ago (Libby 1952). 
An abundance of preserved remains (2504 specimens) 
of food plants, of which only a small number represent 
cultivated species, and the presence of stone mortars in 
zone B, suggest the extensive gathering of wild food 
plants. Fragments of animal bones, as well as projectile 
points and yucca fibers tied to form slip loops, indicate 
some dependence on the hunting and snaring of animals. 
A few specimens of squash (Cucurbita Pepo) and of maize 
cobs and husks suggest an incipient agriculture. 
The final occupation of the cave, represented by zone 
A, is poor in artifacts. However, the presence of sherds, 
a figurine, point fragments and ovoid blades, showed the 
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