Gary Boyer, age 11, of Peoria, Illinois, for his question:

Where are the Islands of Langerhan?

You won't find them in your gift atlas, or in any other atlas of the earth's lands and seas. These so called islands were named for Paul Langerhans who found them, of all places, concealed inside the human body. This was way back in 1869, when medical researchers were grasping the role of the glands in the human anatomy. They knew that the pancreas secretes digestive juices. This pinkish yellow gland is six or more inches wide and about 1 1/2 inches thick. It squats comfortably behind the stomach and contributes its digestive juices through a duct into the duodenum.

Langerhans discovered that the pancreas is populated with small bodies that produce a special endocrine substance of their own. There may be 250,000 to 2 1/2 million of these islets or islands embedded inside the average human pancreas. They manufacture insulin, the glandular secretion that the cells need to use glucose fuel. When the islands of Langerhan fail to contribute enough insulin, unused sugar gets into the blood and the patient suffers from diabetes.