[Methods of the demonstration of the lymphatic vessels]

The methodological tools for the study of the lymphatic vascular system are reviewed. The use of intraparenchymal and retrograde injection techniques often results in poorly reliable specimens, whereas direct injections allow an accurate topographical study of superficial and deep lymphatic vessels. The results obtained by the following methods are discussed: 1) Gerota's method (modified by Ottaviani, 1954) which can be carried out by glass needles and syringes and a mass of Prussian blue; 2) polymers injection as Geon, Rhodopas AX, "Mercox" methyl-methacrylate and Neoprene 842 A. Especially the last yields three-dimensional casts which are matchless in elegance and definition of the relationship between lymphatic and blood vessels; 3) three-dimensional models from serial ultrathin sections, which represent a fundamental tool in order to go through the processes of transendothelial transport; 4) in vivo cinematography documents the lymph pulsed flow, the contractile activity of superficial lymphatic collectors and the play of their valves.