Delta used to cut its limes in 10 slices while Northwest cut them 16 ways. The lime debate was even mentioned at a meeting attended by Mr. Anderson, the chief executive, who was told it saved Northwest about $500,000 a year. In the end, Delta stuck with its 10 slices. But the airline also realized that it had been loading more limes on its flights than it needed. So it is now carrying fewer limes.