The concept of body fluid flow in tissus spaces was first introduced in Bartholin's
Irrigation Theory (1655).
Ludwing and his school (1850) said that body fluid flow from the blood capillaries
to tissue spaces is brought about by filtration，osmosis, and difusion，while Starling (1898) stated that body fluid flow from tissue spaces to blood capillaries is due to colloidal osmosis. Cowdry (1937) claimed that tissue fluid is not a part of the concept of circulation.
The following statement can be made based upon our research.
In the tissue spaces，body fluid flow is seen in the connective tissue，perivascular
space，tissue cavity，and groove between organs.
One of the course for body fluid circulation is blood capillaries一一tissuespaces一一lymphatics一一vein and the flow of such liquid is due to hydrostatic pressure. However，the flow of liquid from tissue spaces to blood capillaries is due to colloidal osmosis.