REACTION OF CELLS TO CROTON OIL 241 
nective-tissue cells move much more rapidly, changing their shape 
and position to such an extent that continuous observation is 
necessary in order to follow individual cells. Thus, in figure 
12, a cell is shown which moved in three hours as great a dis- 
tance as a connective-tissue cell would wander in as many days 
in normal growth. (Compare with fig. B, in article in Journal 
of Anatomy, 1912, vol. 13, p. 368.) 
Fig. 11 Drawing to illustrate radial arrangement of connective-tissue cells 
and their movement toward the croton oil, after the croton oil has been moved 
toward the surface of the fin and its irritating action decreased. Croton oil 
injected twenty-one hours before the drawing was made. The broken lines and 
arrows indicate the direction and approximate distance of movement of the 
connective-tissue cells during eleven hours. No leucocytes shown. Cells 
a, b, g and most others near the globule show the absence of long processes charac- 
teristic of the more rapidly moving cell. Compare with the normal cells x and 
y and others at the right of the drawing. C, d, and e are cells injured by the croton 
oil. Cells d are vacuolated; in cells c and e the walls of the vacuoles have broken 
down, leaving granules suspended in fluid. Cell C is one of the stages of the 
cell shown in figure 10. Cells g and h are the same cells as are shown in figure 12. 
ch, two fixed chromatophores; b. v., blood-vessel; lym, lymphatics. 200. 
