Background and Aims.The presence of novel structures in orchid flowers, including auricles, rostellum and bursicles on the gynostemium and a lobed labellum, has prompted long-standing homology disputes, fuelled by conflicting evidence from a cubs foam finger wide range of sources.Re-assessment of this debate using an improved model is timely, follo

Acid gas is a type of natural gas or any other gas mixture that contains significant quantities of hydrogen sulfide, carbon dioxide, sulfur oxides, nitrogen oxides, hydrogen halides, or similar acidic gases.Acid gases form acidic solutions when dissolved in water.A major cause of acid rain is emissions of sulfur dioxide and nitrogen oxide, which re