Lymph formation and lymph flow involved in the ''inner circulation (Ep
pinger) as vital events are influenced by histomechanics and physicoch
emical factors. The flow dynamics of lymph flow resulting from microci
rculation have recently been attributed to an own discipline, the ''pe
rihemorheology'' (Copley, Witte). Visualization of flow phenomena just
at the origin of the lymph vascular system needs some technical requi
rements encompassing appropriate tissue-models and optimum equipment f
or microscopy, recording, and flow analysis. A review on the history o
f observations on lymph flow phenomena is given. New approaches are de
scribed referring to the rat tongue as appropriate organ for studies o
f peripheral lymph flow. New techniques based on the use of fluorescen
t flow markers are applied. Flow registration is made by ''maximum tra
ce image'' technique. Characteristic flow patterns such as partial and
parallel streams, fountain-like and jet-like currents are found in in
itial lymphatics. Rhythmic lymph flow caused by breathing and suction
activity of the lymph collectors. Transport of labelled cells in perip
heral lymph could be registered as well. The interaction of peripheral
lymph flow with the highly specialized endothelium provides an effect
ive filter function for the elimination of particulate matter by absor
ption and phagocytosis assigning to the prenodal sector of the lymphat
ic system an important defence task. Moreover, endothelial interaction
with different cells (leucocytes, macrophages, mast cells) suggests a
dditional functions for immunobiological mechanisms and control of vas
cular permeability of fine lymphatics. Copyright (C) 1996 Elsevier Sci
ence Ltd