ANNUAL RINGS IN SCALES. 473 
aS . ci 
| fest | | t teal es 
Fic, 2.—Scale curves of one year aa fish. Fic. 10. Pantin curves of scales 
The letters refer to Table I.: the from fish in bad condition. 
figures indicate the first winter's A=abundant tank. 
growth. S=scanty tank. 
H=hot tank. 
The numbers indicate the fish in 
the corresponding tables. 
IN FIGURES 2 TO 10 THE DOTS ON THE CURVES REPRESENT THE 
WIDTHS OF THE SCLERITES OF THE SCALE. THESE ARBI- 
TRARY WIDTHS ARE GIVEN AT THE SIDE OF EACH CURVE. 
IN FIGURES 5, 6, 7, 8, 9 THE FIRST DOT ON THE CURVES 
INDICATES THE WIDTH OF THE LAST SCLERITE ON THE 
SCALE BEFORE THE FISH WAS EXPERIMENTED UPON ; 
THE SECOND DOT INDICATES THE WIDTH OF THE FIRST 
SCLERITE PRODUCED UNDER ARTIFICIAL CONDITIONS. 
IN EACH FIGURE THE LINE DIVIDING A CURVE INTO TWO PARTS 
IS THE LINE OF DEMARCATION BETWEEN TWO PERIODS 
OF THE EXPERIMENT. 
