The volume rendering and surface pages need a high performance graphic card. If you have problems or if the pages show slow responses please check the following 1) Update your browser 2) Make sure WebGL is enabled in your browser 3) Right click on the desktop and open Graphic Stettings of your graphic card.    Make sure that the Graphic Processor is enabled for your browser. Michael Hofmann Department of Comparative Neuroanatomy University of Bonn, Germany Email: mhofmann@uni-bonn.de