Scientists say it just isn't so, but some midwestern farmers swear they can hear corn growing on hot, humid summer nights: a sharp, cracking kind of sound of expanding stalks.

Before the era of indoor plumbing, the corncob played an important part in American hygiene. Hence the term, "rough as a cob." Today the cob is still in demand, for making abrasives, for cellulose, for smoking pipes called Missouri Meercschaums.

Primitive American cultures deified corn, and the grain still inspires celebration throughout the Midwest, where towns like Hoopeston, Ill., and Valparaiso, Ind., hold annual corn festivals.

Corn is native to the Western Hemisphere. It was the basic diet of pre-Hispanic cultures and has been dated as far back as 5200 B.C. in southern Mexico.

Crewmen from Columbus' ships are believed to have been the first Europeans to see corn growing in Cuba, 1492.

The sweet corn that Americans can eat off the cob, canned, frozen, roasted, represents only a tiny fraction of U.S. corn production. The most common corn grown in this country is dent corn, which is dried and shelled for feeding to livestock or for milling. Why the name? It has a small dent in the kernel.