The use of biological stains in the analysis of late Palaeozoic pteridosperm cuticles

The use of biological stains in the cuticular analysis of late Palaeozoic p teridosperms based on specimens from the Stephanian Blanzy-Montceau Basin ( Central France) is discussed. Bismarck Brown, Malachite Green G, Methylene Blue, Methyl Green, Neutral Red, Safranin T, and a double staining with Neu tral Red and Malachite Green G, were tested. Bismarck Brown, Malachite Gree n G, Methylene Blue, and Neutral Red increase contrast and emphasize differ ences in cutinization. The double staining in Neutral Red and Malachite Gre en G enhances the three-dimensional morphology of complex epidermal structu res. Safranin T increases contrast, emphasizes cutinization differences, an d enhances the three-dimensional morphology of complex epidermal features. The colour photography of cuticles is normally not affected by the presence of stains, but some stains mask black-and-white half-tones. (C) 2000 Elsev ier Science B.V. All rights reserved.