Meantime it is interesting to observe that the log-jam of the independent inventionists is weakening a bit. When the International Congress of Americanists met in New York in 1949, the hitherto conservative and autochthonous American Museum of Natural History presented for the instruction and delectation of the Congress a rather elaborate exhibition of parallelisms between the cultural traits of the Old World and the New. A follow-up to this noteworthy gathering was a symposium of many of the same anthropologists at a meeting, two years later, of the American Association for the Advancement of Science. The theme was “Prehistoric and Historic Asia: Transpacific Contacts with the New World.”[21] The question of contacts was not squelched, but there was no substantial progress in finding answers. The symposium focused the problem on two tests of possible diffusion. These concerned domesticated plants and formal art. The strongest cases that can be made for the diffusion of any plant concern the _Lagenaria_ gourd, cotton, the sweet potato, and the coconut. None of these ranks as a staple of subsistence, and two of them are not even food plants. Thus Old World and New World crops are mutually exclusive. The four plants that we have mentioned may have had world-wide distribution before man reached the New World; they may have followed the first contacts of white men with the Americas; there is only a remote possibility that they crossed the ocean through natural agencies. In formal art—or perhaps we should say religious art—there are some tantalizing prospects for rather recent Asia-America diffusion. Gordon Ekholm, of the American Museum of Natural History, has listed a number of these. He suggests that the time of contact would have been about 700 A.D. This, you will note, is much too late to do much in shaping American civilization. At the most, it would have furnished no more than a bit of Asiatic frosting upon the cake of American civilization. Drawing upon elements of art from India, southeast Asia, and Indonesia, Ekholm points to similarities in Maya, Mexican, or other native American art, where parallels seem to exist in such things as a trefoil arch, a sacred tree or cross, tiger thrones, conch-shell-and-plant, Atlantean figures, monster doorways, serpent columns and balustrades, and others.[22] The comparisons are provocative, to say the least. In the Maya area, where most of the suspected influence of Asia occurs, many forms of art steadily deteriorated during the period when, theoretically, Asiatic stimulation would have been most pronounced.