Howard H. Seliger, Hopkins biology professor

Howard H. Seliger, a retired Johns Hopkins University biology professor who fulfilled a childhood fascination with fireflies by later investigating the science behind their light-making properties, died of coronary artery disease Dec. 20 at his Mount Washington home. He was 88.

Family members said that he was an expert on bioluminescence. He helped to show that fireflies and microorganisms found in bioluminescent bodies of water have enzymes that trigger a chemical reaction that make them light up.

Dr. Seliger was also principal scientist at the Chesapeake Bay Institute from 1972 to 1989.

"Two major events have directed my scientific career. When I was about 10 years old, I saw my first firefly. It was at Camp Northover, New Jersey, run by the Christodora Settlement House on the lower East Side of Manhattan," he said in an autobiographical essay. "From then on I became fascinated with light, and with how in the world this little insect that I held in my hand could produce light, when the only sources of light in my experience came from hot objects; sunlight, incandescent lights, and colored neon lights."

Born in New York City, he was the son of a waiter and a homemaker. He graduated from Townsend Harris High School and earned a degree at the City College of New York. He served in the Army Air Forces during World War II and earned a master's degree from Purdue University and a doctorate in physics at the University of Maryland, College Park.

From 1948 to 1958, he was a senior physicist in the Radioactivity Division of the National Bureau of Standards in Washington, where he studied radioactivity measurement.

In his autobiographical essay, he said that a scientific colleague recommended him to the Guggenheim Foundation for a fellowship.

"The award of the fellowship in 1958 marked the definitive turning point in my career," Dr. Seliger wrote. "I had heard that W.D. McElroy, chairman of the Biology Department at the Johns Hopkins University, was working on the biochemistry of the light production by fireflies. ... Here was the perfect opportunity. ... I came to see him, and within the hour he welcomed me into his department."

He spent his fellowship year in the Johns Hopkins biology department.

"He made a big decision. He was young and doing very well at the Bureau of Standards as a nuclear physicist," said William Biggley, his research assistant for 38 years. "He changed careers and made good use of his expertise in mathematics and physics in the field of biology."

At the time his department was paying 25 cents for 100 fireflies caught and brought to the scientists at the Homewood campus. Many Baltimore children spent parts of their summers catching lightning bugs in glass jars.

"McElroy introduced me to phytoplankton in bioluminescent bays in Jamaica, West Indies, and after a few years we unraveled the mechanism for the growth, migration, and retention of algal blooms in bioluminescent bays, a two-layer subsurface flow," he wrote in his essay. "I then showed that this same mechanism was common, not only for bioluminescent phytoplankton blooms in bays and coastal waters (Chesapeake Bay, Florida, Puerto Rico, the Pacific islands, the kingdom of Brunei Darussalam), but for the formation, migration, and retention of all phytoplankton blooms."

After receiving the Guggenheim Fellowship, Dr. Seliger joined the Johns Hopkins faculty. A professor of biology, he conducted research and taught until he was 75.

"Firefly chemistry is being used in medical research to signal whether tumor cells respond to drugs before the medications are given to cancer patients," a 1996 Baltimore Sun article said. "Bioluminescence is also used to show if drugs are working to kill bacteria that cause tuberculosis, among other bacterial diseases."

Dr. Seliger was the president of the American Society for Photobiology in 1980-981. He was a fellow at the American Physical Society and the American Association for the Advancement of Science.

He also held other posts at Johns Hopkins. He was radiation safety officer, chairman of the Committee on Radiation Control, professor of the department of environmental health sciences at the Johns Hopkins School of Hygiene and Public Health and director of the Division of Environmental Chemistry, also at the School of Hygiene and Public Health.

"He was dedicated to science and dedicated to doing it right," said his colleague, Mr. Biggley, who lives in Jarrettsville. "Howard Seliger wore a lot of hats. The university was very lucky to have him. He started a big research group on the Chesapeake Bay and studied algae, phytoplankton, primary productivity."

Family members and friends said he rescued live turtles he found by the side of the road. He gave them to lab assistants, who released them at the Loch Raven watershed.

Survivors include his wife of 69 years, the former Beatrice Semel; two daughters, Carole Rollinson of Leesburg, Va., and Susan Seliger of New York City; two grandsons; and a great-grandson.

Plans for a memorial service are incomplete.