Vergleichend-anatomische Untersuchungen über einen transepithelialen Flüssigkeitsstrom in das Lumen der Kloake von Vögeln

Comparative anatomical studies on transepithelial fluid migration into the lumen of the cloaca in birds In the rooster the fluid migration originates principally from lymph capillaries and ends in the interstitium of the lymphfolds. In the male duck, coot and pigeon this phenomenon occurs in a corresponding zone of transudation. In these birds the fluid migration originates principally in blood capillaries, however. From the interstitium the fluid passes through intercellular spaces of the epithelium into the lumen of the cloaca where it appears as a transparent fluid. In all examined species immunocompetent cells migrate into the cloaca with the fluid. These cells produce the immunoglobulins which have been found in the transparent cloacal fluid of the rooster.