In this part of the cavern the rivulet deposits blackish earth, a mixture of silex, clay and vegetable detritus. We walked in thick mud to a place where, to our shock, we discovered underground vegetation. The seeds that the birds bring into the grotto to feed to their chicks germinate wherever they fall on to earth covering the calcareous Incrustations. Blanched stalks with rudimentary leaves rose to some 2 feet. It was impossible to identify the plants as the absence of light had completely transformed their form, color and aspect. These traces of plant life in the dark struck the Indians, usually so stupid and difficult to impress. They examined the plants in a silence inspired by a place they fear. You could have said these pale, deformed, underground plants seemed like ghosts banished from the earth's surface. For me, however, they recalled one of the happiest days of my youth when during a long stay at the Freiberg mines I began my research into the effects of blanching plants.