226 ELIOT R. CLARK AND ELEANOR LINTON CLARK 
fluid, and is finally excluded. The heap of epidermal cells 
covering the globule is apparently thrown off at the same time. 
As soon as the globule is extruded, the connective-tissue cells 
recover their normal shape and the circulation in the blood- 
vessels of the injured region is restored. The stationary leu- 
Figs. 1 to 5 A series of sketches showing the general pictures of an inflam- 
mation produced by injecting a drop of croton oil (10 per cent in paraffin oil) 
into the dorsal fin of a Hyla larva. The connective-tissue cells are shown in 
solid black, the pigmented leucocytes are dotted, and wandering cells in outline. 
x 188. 
Fig. 1 Sketch started May 30th at 10:50 A.M., immediately after the injec- 
tion of croton oil. The broken line indicates the extent of the injured area as 
evidenced by the granulation of the connective-tissue cells. The paths of some 
of the migrating leucocytes are indicated by dotted lines and arrows. X marks 
the location of a sessile leucocyte at 12:15 P.M. Lym., lymphatic capillary; 
B.V., blood-vessel; 0.G., oil globule. 
cocytes, which had assumed the form of small connective-tissue 
cells, now draw in their processes and resume their normal 
amoeboid shape. However, within an hour or two, all of the 
leucocytes of the region have become motionless again, but with 
a spherical form (fig. 3). 
