441 



Series A. On August 3, twenty-one fish varying from 91 ni.ni. to 114 

 m.m. were operated on and placed in tank A. in rnnning sea water. The 

 scales shown in ])]ate II were all taken from this series. No fish from 

 this series were lost dm lug the experiment. 



Plate II. Showing th3 process of differentiation in regenerating scales. All operations 

 wore performed on Aug. 3. Numbers in low^r right hand corner indicate the day of tlje 

 month on which the fish were killed. 



Series B. August 3, twelve fish varying from 72 m.m. to SG m.m. were 

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

 one by sporozoan 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 ex- 

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



