430 



ELIOT R^- CLARK AND ELEANOR LINTON CLARK 



tion to the brown pif^incnt. The chemical nature of these drop- 

 lets was not determined. 



The response of lymphatic endothelium to the presence of the 

 sodium oleate was similar to the reaction toward olive oil. 

 Nearby lymphatics sent out processes which extended toward 

 the site of injection, increased in size, acquired a lumen, and 



May 11 



May 16 



May 13 



c. t lb ^G>. 



A lym 



Fig. 4 Series showing the reaction of a lymphatic capillary toward an in- 

 jected globule of oleic acid (soap). Soon after the injection, May 11, the lym- 

 phatic sprout extends in the opposite direction from the injected mass. On 

 May 13, it is shown approaching the mass and in the last sketch it has reached 

 it. lym., lymphatic; p.l., pigmented leucocyte; c.l., clear leucocyte. Enlarge- 

 ment = 187x. Drawn with camera lucida. 



finally came into contact with the pigmented leucocytes surround- 

 ing the soap (fig. 4). Continuous observations of the region 

 were made and the movements of each leucocyte in the field was 

 followed, by means' of drawings made at intervals of about five 

 minutes. It then became evident that pigmented leucocytes 

 were continually moving away from the injected mass and wan- 

 dering up to a nearby lymphatic capillary. After remaining for 



