REACTION OF CELLS TO CROTON OIL 245 
of a lymphatic capillary near the site of injury shows that such 
leucocytes from the tissue wander through the wall into the 
lymphatic, move down the vessel, and crawl out again at the 
tip, nearer the globule of croton oil (fig. 14). 
325 
Fig. 14 1) Illustrates the migration of a leucocyte from the tissue into a 
lymphatic capillary, down toward the tip nearer the site of injection, and out 
again. Lymphatic sketched at 2:30 P.M. A, B, and C are three different leuco- 
cytes. The arrows and dotted lines show the respective paths which they followed. 
X213. 2) shows the appearance of a part of the lymphatic near the tip at 3:25 
P.M., at the moment when a leucocyte (A) is in the act of emerging and illustrates 
the deceptive appearance of endothelial proliferation which accompanies the 
phenomenon. As seen in sketch (1), leucocyte A entered the lymphatic higher 
up at 3:05, and at 3:30 it was again outside the vessel. 213. 
As in the case of the blood-vessels, we kept records of the 
lymph-vessels and of their endothelial nuclei, both inside and 
outside the ‘granular area,’ in several different larvae. The 
lymphatic sprouts within the ‘granular’ zone, which had become 
vacuolated while the croton oil was present, often retracted, 
