Vili LIST OF ILLUSTRATIONS 
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PHOTOGRAPHING A DACE, LIGHTED BOTH FROM ABOVE AND FROM 
IN FRONT . . . . . . . 5 . 
DACE . . . . . . . . . 
DACE REFLECTING ITS DARK SURROUNDINGS . . 5 . 
PHOTOGRAPHING A DACE, LIGHTED ENTIRELY FROM ABOVE . 
DACE SWIMMING FREE IN THE POND . . . . . 
SHOAL OF YOUNG RUDD SEEN AGAINST THE SURFACE OF THE 
WATER FROM THE BOTTOM OF THE POND . . . . 
ORANGE, BLACK, AND YELLOW PIGMENT CELLS IN SKIN OF LOACH 
PIKE WITH TAIL IN THE LIGHT ° . . . . . 
PIKE WITH HEAD IN THE LIGHT . . . . 
TENCH, AS ACTUALLY COLOURED . . . 
TENCH, AS SEEN UNDER THREE FEET OF WATER IN THE POND. 
TENCH, AS SEEN UNDER SIX INCHES OF WATER IN THE POND . 
STONE LOACH, SHOWING ACTUAL ARRANGEMENT OF COLOUR AND 
MARKINGS ° . . . . : . . . 
STONE LOACH, SHOWING HOW MARKINGS ALONE DO NOT CONCEAL 
STONE LOACH, SHOWING HOW MARKINGS SEEN ON A UNIFORMLY 
COLOURED FISH DO CONCEAL . . . . 
PERCH AS WE SEE IT IN A TANK . . . 
PERCH AS IT APPEARS TO OTHER FISH IN NATURAL ENVIRONMENTS 
LEMON SOLE SEEN AGAINST A WHITE BACKGROUND . . . 
THE SAME FISH IN NATURAL SURROUNDINGS . . 
SKIN FROM A STONE LOACH LIVING ON A MUDDY BOTTOM . 
SKIN FROM A STONE LOACH LIVING ON A SHINGLY BOTTOM 
BABY PIKE SHOWING BARS . . . . 
PIKE WITH BARS CHANGING INTO SPOTS . . . 
DEAD PIKE, 21 LBS. IN WEIGHT, SHOWING SPOTS . . . 
RUFFE, SHOWING THE FIN ON THE BACK AS A WEAPON OF DEFENCE 
COTTUS IN A WARNING ATTITUDE . . . . . 
BLENNY ASSUMING A WARNING ATTITUDE . . . . 
DOG-FISH . . . . . . . . . . 
FEMALE DOG-FISH SWIMMING ROUND A ROCK . . . . 
GROWTH OF THE EMBRYO RAY . . . . . . 
RAY ONE MONTH OLD . . . . . . . . 
UNDER-SURFACE OF RAY, SHOWING MOUTH, NOSTRILS, AND GILL 
SLITS » . . . . . . . . 
YOUNG THORNBACK RAY LYING ON THE BOTTOM OF THE SEA . 
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