When sphingolipids were discovered a century ago by the physician chemist Johann Thudichum, their biologicalrole seemed as enigmatic as the Sphinx, for whichhe therefore named them. In humans. at least 60 different sphingolipids have been identified in cellular membranes. Many of these are especially prominentin the plasma membranes of neurons and some are clearly recognition sites on the cell surface. but for Johann Thudichum. only a few sphingolipids has a 1829-1901 specificfunction been discovered.When sphingolipids were discovered a century ago by the physician chemist Johann Thudichum, their biological role seemed as enigmatic as the Sphinx, for which he therefore named them. In humans, at least 60 different sphingolipids have been identified in cellular membranes. Many of these are especially prominent in the plasma membranes of neurons, and some are clearly recognition sites on the cell surface, but for only a few sphingolipids has a specific function been discovered