IDEALLY A BIENNALE IS MORE than an international exhibition of current art events. It is a research laboratory, to which the artists from each participating country bring their latest findings. It has been proven again and again over the years that art movements of real vitality are more than national; they leap borders and often linger abroad with great effect before and after they are valued at home. While the great burden of transmitting the news in the world of art is on the traveling exhibition, the traveling artist and the art magazines, the Biennales also do their part. When they have