Longtime Chilmark homeowner Dr. Donald B. Martin, who spent the past 50 summers coming to the Vineyard, died Nov. 1, 2006. He was 79.

Dr. Martin bought a home on South Road in 1966 with his wife, Anne, and counted South Beach among his favorite places in the world.

He celebrated his 50th wedding anniversary in Chilmark last September, with a catered dinner at his home.

Dr. Martin died at the Hospital of the University of Pennsylvania, where he had trained generations of doctors as director of the medical residency program. The cause was complications from Parkinson's disease.

An internationally known expert in the treatment of diabetes, Dr. Martin was dedicated to his residents and at the forefront of a movement in medical education to make residency more humane for doctors during their training.

Dr. Martin, who co-authored numerous articles in medical journals including the Journal of the American Medical Association, Lancet and Science, was known for his modesty, generosity and quick but kind wit.

He was a Fulbright Scholar in Paris in 1962 and a fellow of the John Simon Guggenheim Memorial Foundation in Geneva in 1974.

The Hospital of the University of Pennsylvania recruited Dr. Martin in 1979 to be the founding director of the Rodebaugh Center for Diabetes Research and Education and made him associate chairman of the department of medicine in 1985.

Directing the internal medicine residency program from 1985 to 1996 brought Dr. Martin his greatest satisfaction. His absolute commitment to the education and well-being of students and residents made him a much-loved member of Penn's medical faculty.

Dr. Martin received the Donna K. McCurdy Department of Medicine Housestaff Teaching Award in 1990, the Penn Pearls Teaching Award for excellence in student teaching in 1993, and the Medical Student Government Teaching Award for Clinical Medicine in 1994.

The Donald B. Martin Teaching Service Awards for the outstanding teacher on the faculty was established by the University of Pennsylvania Medical School in 1996, the same year Dr. Martin became a professor emeritus.

Conferring a prestigious mastership on Dr. Martin in 1997, the Board of Regents of the American College of Physicians described him as "a superb clinician with a broad range of clinical knowledge and the ability to make difficult concepts accessible."

A native of West Philadelphia, Dr. Martin joined the Navy in 1945 after graduating from the William Penn Charter School. He left the service in 1946 and attended Haverford College, graduating Phi Beta Kappa in 1950. He received his medical degree cum laude from Harvard Medical School in 1954.

Following his training as an endocrinologist, Dr. Martin taught at Harvard Medical School and worked at Massachusetts General Hospital. He was chief of the diabetes unit there from 1967 until 1979, when he left for Penn.

In addition to teaching, Dr. Martin was an avid birdwatcher, a devoted reader of history and had such a passion for classical music he took up the French horn in his late 60s.

Survivors include his wife of 50 years, Anne Holmes Martin of Bryn Mawr, Pa.; his four children, Dr. Jonathan Martin of Rehoboth, David Martin of Lincoln, Neb., Lydia Martin of Bryn Mawr, Pa., and Liza Martin of Hartford, Conn.; and 11 grandchildren.