Certain phenomena in the region of the initial lymphatics during clinical examination (indirect lymphography and microlymphography)--namely build-up and course and filling and diffusion--have still to be elucidated. The glutaraldehyde and MERCOX methods were used to simulate indirect application conditions in clinical procedures in skin specimens (human and pig) which were then examined by scanning electron microscopy. The results presented include novel findings on the microtopography of these lymph vessels and the typology of filling refluxes which are of importance when indirect imaging techniques are employed. Various speeds of application were used and the function of the opening apparatus with previously undescribed structures (endothelial bridges and connective tissue trabeculae) was taken into consideration. Recommendations aimed at standardizing the nomenclature of parietal structures and sections of the lymphatics have been incorporated in the report.