3i6 



THE POPULAR SCIENCE MONTHLY 



Fig. 4. Prehistoric Rubber found 

 14 Miles from Sasco, Arizona. 



But the earlier history of the 

 industry in Mexico has a larger 

 romance than can well be re- 

 lated in the short space here 

 allotted. The more salient points 

 only may be mentioned. Just as 

 the Mayas in the south, and in 

 the Amazon region, made playing 

 1 tails of latex rubber, so, in the 

 north, guayule rubber was known 

 and used by the aborigines. But 

 the task of extraction was for 

 these more indirect, for they 

 chewed the bark of the plant, in 

 order to separate out the fibrous 

 tissue and to agglomerate the 

 rubber. Assiduous mastication 

 on the part of a sufficient num- 

 ber of devotees to pelota turned out in a short time a resilient if 

 ■crude rubber ball. There is evidence that this plaything found its 

 way by barter to the coast of the Gulf of California and probably 

 the peoples to the north and east also obtained it. It is a matter of 

 unusual interest that the aboriginal Papagos used rubber. Late in 

 1909 an olla, or earthenware jar, was unearthed at some depth on the 

 site of an ancient village near Sasco, Ariz. In it were two round 

 masses of rubber which, aside from a vitreous and fissured external 

 layer, still displayed the texture, resiliency and odor of a dry and al- 

 most resin-free product. A generous piece (Fig. 5) of one of the 

 masses was presented to the 

 writer by Professor A. H. 

 Forbes, of Tucson, Ariz., for 

 study, but the microscopic evi- 

 dence does not support the most 

 natural supposition that it is 

 guayule rubber, but more prob- 

 ably that it is a latex rubber 

 which found its way northward 

 from the more remote parts of 

 Mexico. It is fairly certain, 

 therefore, that rubber was an 

 article of barter over a rather 

 wide stretch of country. 



At the present time not only 

 guayule, but two at least of its 



congeners, 



mariola " (Parthe- 



Fig. 5. Microscopic Appearance of 

 Guayule Rubber in the Cells of the 

 Rubber-bearing Tissue. 



