viii LIST OF ILLUSTRATIONS 



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PHOTOGRAPHING A DACE, LIGHTED BOTH FROM ABOVE AND FROM \ 



IN FRONT . , . , . i . . h 24 



DACE . . . . . . * . J 



DACE REFLECTING ITS DARK SURROUNDINGS . . * * I 24 



PHOTOGRAPHING A DACE, LIGHTED ENTIRELY FROM ABOVE . ) 



DACE SWIMMING FREE IN THE POND ,i . , . 26 



SHOAL OF YOUNG RUDD SEEN AGAINST THE SURFACE OF THE 



WATER FROM THE BOTTOM OF THE POND .... 26 



ORANGE, BLACK, AND YELLOW PIGMENT CELLS IN SKIN OF LOACH \ 

 PIKE WITH TAIL IN THE LIGHT . . . . . . V 28 



PIKE WITH HEAD IN THE LIGHT . . . . . . J 



TENCH, AS ACTUALLY COLOURED . . . . . ~\ 



TENCH, AS SEEN UNDER THREE FEET OF WATER IN THE POND . V 30 

 TENCH, AS SEEN UNDER SIX INCHES OF WATER IN THE POND . J 

 STONE LOACH, SHOWING ACTUAL ARRANGEMENT OF COLOUR AND 



MARKINGS . . -V , . 



STONE LOACH, SHOWING HOW MARKINGS ALONE DO NOT CONCEAL J- 30 

 STONE LOACH, SHOWING HOW MARKINGS SEEN ON A UNIFORMLY 



COLOURED FISH DO CONCEAL ...... 



PERCH AS WE SEE IT IN A TANK . . . . ' ) 09 



PERCH AS IT APPEARS TO OTHER FISH IN NATURAL ENVIRONMENTS I 

 LEMON SOLE SEEN AGAINST A WHITE BACKGROUND . . . | 



THE SAME FISH IN NATURAL SURROUNDINGS . . . . j 



SKIN FROM A STONE LOACH LIVING ON A MUDDY BOTTOM . ] 



SKIN FROM A STONE LOACH LIVING ON A SHINGLY BOTTOM . J 



BABY PIKE SHOWING BARS . . . . , , . . ~\ 



PIKE WITH BARS CHANGING INTO SPOTS . . . . V 36 



DEAD PIKE, 21 LBS. IN WEIGHT, SHOWING SPOTS . . . J 



RUFFE, SHOWING THE FIN ON THE BACK AS A WEAPON OF DEFENCE \ 

 COTTUS IN A WARNING ATTITUDE . . . . . V 38 



BLENNY ASSUMING A WARNING ATTITUDE . . ." . J 



DOG-FISH . . . | 4Q 



FEMALE DOG-FISH SWIMMING ROUND A ROCK . . . . j 



GROWTH OF THE EMBRYO RAY V . . . . . 42 



RAY ONE MONTH OLD . * . . . . "| 



UNDER-SURFACE OF RAY, SHOWING MOUTH, NOSTRILS, AND GILL L 42 



SLITS . . <. . , . . . V. . . ) 



YOUNG THORNBACK RAY LYING ON THE BOTTOM OF THE SEA . 44 



