20 27 44 



days after start expt 



FIGURE 2 

 ti ons of 

 over t ime . 



Increase in relative propor- 

 sweepers on adjacent regions 



CD 



c 



CO 



.c 

 o 



CD 

 > 



4-> 



E 

 o 



2 



1- 







1- 



B — 



20 27 44 



days after start expt 



■2. 



60 



FIGURE 3. Cumulative changes in the 

 number of polyps with sweepers. on 

 adjacent (A) and non-adjacent (B) 

 regions. Each value incorporates 

 summed changes from all previous 

 observa t ions. 



64 



