441 



Scries A. On Aii.u;ust 3, t\vent,v-<me fish varyint,' from 01 m.in. to 114 

 m.in. were operated on and placiMl in tank A. in running sea water. The 

 scales sliown in i)late II were all taken from this series. No fish from 

 this series were lost dniing the experiment. 



Plate II. Showing th-' process of differentiation in regenerating scales. All operations 

 were performed on Aug. 3. Numbers in lower right hand corner indicate the day of the 

 month on which the fish were killed. 



Scries B. August 3. twelve fish varying from 72 m.m. to S(i m.m. were 

 operated on and placed in tank B. In this series two individuals were lost, 

 one by sjiorozoan infection and one by being accidentally caught in the 

 cutlet of the tank. 



Series C. On August 4, five fish were totally denuded of scales e.Y- 

 oept a few accidentally left around the base of the fins. It was very 



