REACTION OF LYMPHATIC ENDOTHELIUM 439 



of the living cells and their reaction toward the various sub- 

 stances, it can be stated that leucocytes migrated toward the 

 site of injection and actively phagocytized the fat in the form of 

 small droplets and that subsequently the fat within the cells ap- 

 parently became split up into a finer and finer emulsion (the 

 brown pigment granules) and that, eventually, it was changed to 

 a soluble form, in which state it was absorbed by the lymphatic 

 capillaries. 



Fig. 6 Illustrates relationship of leucocytes to lymphatics during the ab- 

 sorption of a globule of olive oil. Oil injected May 5. This drawing made 

 May 15. This is the same specimen and oil globule as that shown in figure 2. 

 The globule is surrounded by pigmented leucocytes some of them containing 

 small oil globules. The smaller globule to the left has become separated from 

 the main globule. The oil is represented by the color, lym., lymphatic; m.c., 

 mesenchyme cell; p.Z.. pigmented leucocytes; y, pigmented leucocyte, closely 

 adherent to the tip of lymphatic. Enlargement = 187x. Drawn with camera 

 lucida. 



This characteristic mode of response toward injected fat on the 

 part of the leucocytes of the tadpole's tail, stands in marked 

 contrast to the behavior of the same type of cells toward the 

 injected globules of paraffin oil. In the case of the experiments 

 with paraffin oil, as described in the earlier article (5), leucocytes 

 collected around the oil soon after its injection. This leuco- 

 cytosis was always transitory. In some cases in which this tem- 

 porary reaction was intense, probably as a result of infection, 

 the globule was extruded. In most instances, the leucocytosis 

 had subsided, after three or four days and, in all cases, at the 

 end of a few days more. When individual leucocytes were 



