PREHISTORIC ART. 459 



which are doubtless silicilied leraains of foraininifera, such as are uot infrequent in 

 siliceons nodules fonud in limestone. There is nothing in the series in the least 

 resembling true nephrite or jadeite. 



The concliidiug seuteuce leaves the discovery of the origiu of jade 

 material, of which the Costa Rica prehistoric imi)leii]eiits were made, 

 as much an unsolved problem as ever. But negative results from the 

 searches of an experienced geologist made on tlie spot are of more 

 value than has been generally admitted, and the thanks of i)rehistoric 

 anthropologists are due to Mr. Sjogren for his interest and ettbrts. It 

 is certainly remarkable that, with the thousands of prehistoric imple- 

 ments from Mexico and Central America, no specimens of the natural 

 material has ever been found in any of those countries. 



There are other views which seem to narrow the question of jade 

 migration, if they do not elucidate it. It would appear highly imi)roba 

 ble that any such migration of peoples could have been made by land 

 between the place of origiu in Burmah and the place of its discovery 

 in Mexico and Central America. We can scarcely conceive of a 

 migration, comprised of however great or small numbers, which would 

 start from Burmah overland by way of Bering Straits for Mexico 

 and Central America, carrying with them such small implements 

 and in such great numbers. If they did, these implements would 

 run great risks of being lost. Arrived in Alaska, the emigrants ought 

 to have found some traces or specimens of the nephrite, wrought or 

 unwrought, of which we now find so many. One or two hypotheses 

 force themselves upon us: The emigrants (from Burmah) might have 

 left some of their own jadeite implements in Alaska or obtained some 

 of the nephrite. No traces have been found of either. Theu these 

 emigrants would have started on their southwestern trip, a distance of 

 several thousand miles, to Mexico, without leaving anywhere any trace 

 of jadeite implements. Arrived at Mexico, and thence on through Cen- 

 tral America, are to be found implements, all of jadeite, by the thousand, 

 but none of nephrite. If these emigrants traveled by land from 

 Burmah to Mexico, crossing at Bering Straits, it would involve a long 

 and necessarily tedious journey. In Alaska these emigrants would 

 enter a country where there was a mountain of this precious mineral, 

 the prehistoric inhabitants of which well knew how to make it into 

 implements. No other imidements or objects, of this or similar mate- 

 rial, have been found along the indicated route which would serve as 

 extraneous evidence of such migration. 



The foregoing argument seems satisfactory to the author against a 

 migration of jade or jade implements by land from Burmah to Mexico or 

 Central America. This leaves only the ocean as a means of migration, 

 and that such a journey should have been voluntarily made across such 

 an ocean seems almost incredible. It would appear, in view of the diffi- 

 culties and obstacles to such journeys or migrations, either by land or 

 sea, that the only course left to deal with the jade question is to await 

 further developments and discoveries. 



