[New knowledge of the structural principle of lymph formation]

The structural conditions in the zone of transition from the tissue to the lymphatics are described on the basis of electron microscopic (especially scanning electron microscopic) and light microscopic results. Here, the interstitium with its fiber organization and the system of prelymphatic channels as well as the wall characteristics of the initial lymphatics and precollectors are given particular consideration. The flow conditions, the stretching ability and the permeability of the very fine lymphatics are investigated in the model of the rat tongue by means of a special vital microscopic technique using various labelling substances. Against the background of the morphological and rheological findings, the question of lymph formation is analysed on the basis of new hypothetical criteria for the mechanisms involved.