Books: IROISLECXE

THE LONGEST CAVE by ROGER W. BRUCKER and

RICHARD A. WATSON 316 pages. Knopf. $12.95.

Flatlanders never have been able to understand mountain climbers, and not even mountain climbers understand the pale, mud-smeared troglodytes whose curious passion it is to worm their way down through the clammy dark into the deepest and narrowest capillaries of caves. These low adventurers are brave, but their squirmy feats seem inglorious. If, slithering downward, one of them carried a banner, its strange device might well read !IROISLECXE.

Now come a Yellow Springs, Ohio, advertising man named Roger Brucker, and Richard Watson, a philosophy professor at Washington University...