THE PASSAGE OF VISIBLE PARTICLES THROUGH THE WALLS OF BLOOD CAPILLARIES AND INTO THE LYMPH STREAM

Abstract

Exps. were carried out which show that visible particles of many different sizes and physical characteristics pass through the uninjured walls of blood capillaries and frequently into lymphatics. Graphite (particle size 1[mu]) was observed to leave blood capillaries in the tongue and web of the frog. Calcite (1-2[mu]), behaved similarly in the mesenteric capillaries. The material could easily be found in lymph from the foot of the frog and also in lymph from the foot of unanesthetized dogs. Pneumo-cocci injected intraven. in the rabbit appeared rapidly in thoracic duct, cervical and foot lymph. Erythrocytes readily became extravascular and were found in the lymph if the part was exercised or if the venous pressure was increased. No extra leakage of blood proteins accompanied this escape of red cells. Microfilariae 40 X 5[mu] readily left blood capillaries and entered lymphatics; their escape was accomplished without injury to the blood capillaries. There is no evidence as to favored points of particle egress and the final nature of the passage is not known.