Unlike the first fall of snow or the vernal equinox, the opening day of the trout season is only an arbitrary, man-made notation on the calendar. Yet the mystical attraction of that first dawn is so compelling that no veritable angler would willingly forego it. Little wonder then that on opening day the loneliest place in Shrewsbury, Mass. used to be Calvin Coolidge school, which overlooks Lake Quinsigamond and adjoins two fine ponds. Musing on this annual total absenteeism of his charges, Lester Dyer (right, above), the school's principal, and himself an ardent angler, came up with a solution brilliant in its simplicity: an opening-day fish derby, conducted from dawn to the 8:30 school bell with all catches judged during the first school period. A score of prizes are awarded for the more imposing catches while the unrewarded surely take comfort in Dame Juliana's dictum that "it will be a very great pleasure to you to see the fair bright shining-scaled fishes deceived by your crafty means."