MDI Biological Laboratory
A timeline of MDI Bio Lab’s odyssey of discovery

125 Years of
Science by the Sea

The MDI Biological Laboratory started out in 1898 as a summer school for biology students. Today, we’re an independent, year-round, international hub for the science of regeneration and aging. Ours is a dynamic history of personalities and disciplines brought together in an informal but inspiring environment for the rigorous study of comparative biology. While animal models and scientific questions change over time, our commitment to collaboration and collegiality holds fast.

Adapted from the writings of David. H. Evans, Ph.D.*

“What a splendid and useful thing it would be if we could provide here, in a spot so full of biologic interest and unsolved biologic problems, so rich in various beauty and locked around by the cool northern sea... a home, however simple, for [scientists] to work... on a fresh field of life.”
George B. Dorr
Philanthropist who championed the Bio Lab’s move to Salisbury Cove in 1921


Early leaders: marine organisms & model systems for human physiology

In 1898 The Tufts Summer School of Biology at Potts Point offers its first season of instruction and research in South Harpswell, Maine. Biologist John S. Kingsley is its founding director.

John Sterling Kingsley

John Sterling Kingsley’s research focused on vertebrate zoology, comparative zoology and the anatomy of vertebrates. Over his lifetime, Kingsley contributed hundreds of scientific drawings and scholarly work.

Born in 1854, Kingsley created a chemical journal at the age of twelve. He graduated from Williams College in 1875, and ten years later earned a doctorate at Princeton University; his dissertation focused on the embryology of the horseshoe crab.

An exceptional artist, he funded his own research by making illustrations for various scientific publications and lectures. Later, when he was the Chair of Biology at Tufts University, one student wrote that Kingsley’s lectures “illustrated by free-hand drawings on the blackboard and enlivened by flashes of humor will long be remembered as models of lucid exposition.”

In 1898, Kingsley established a new research station in South Harpswell, Maine, on Casco Bay: “The Tufts Summer School of Biology”. A rented cottage served as its first classroom but by 1901 classes were held in a purpose-built laboratory.

During the summer term, courses in invertebrate and vertebrate biology were taught, while accomplished scientists pursued their research — among them luminaries such as Nobel Prize winner Thomas Hunt Morgan and Edmund B. Wilson, the father of Evolutionary Development.

In 1921 Kingsley moved to California, where he published The Vertebrate Skeleton. He died in 1929 before a planned visit to the Harpswell Laboratory’s successor, the Mt. Desert Island Biological Laboratory. The MDI Bio Lab’s Executive Committee wrote that biology had lost one of its most distinguished representatives, adding that “Dr. Kingsley was one of the first to perceive the need of a marine biological station north of Cape Cod. His faith in the future never faltered.”

In recognition of his importance to MDI Bio Lab history, the lab’s main office building was named for Kingsley in 1987.


As with many of the summer school’s early scientists, Herbert V. Neal and family live in tents their first two seasons in Harpswell. A renowned theorist and teacher of biology, Neal would describe secretory cells in skate fish that become known as Neal Cells.

Herbert V. Neal

Herbert Neal’s research focused on the nervous system of marine organisms, most notably the spiny dogfish shark.

Born in Lewiston, Maine, in 1869, Neal earned his Ph.D. in Zoology from Harvard University in 1896. He worked at the Harpswell Laboratory beginning in 1907, eventually serving as Assistant Director, then Director, from 1907 to 1916. During World War I, Neal served as a Captain in Italy. He then became “a fixture” at what became the Mt. Desert Island Biological Laboratory from 1922 to 1940.

In 1922, his first summer in Salisbury Cove, Neal was one of the senior scientists who lent the laboratory $1000 to purchase a tract of land next to the original MDI Bio Lab property. Louise DeKoven Bowen, who owned a summer residence nearby, donated $2500 for the purchase as well, with the proviso that Neal and his family would be given a cottage and barn located there.

In 1926, Neal became MDI Bio Lab’s second director. For the next three decades he and his wife, Helen gave an informal course in field biology to local children. Eighty years later, one of those students, David Rockefeller, remembered fondly that the course “gave me an initial start and interest in natural history, which I think is retrospect was important in my having become much more deeply interested at a later time in my life”.

Neal is remembered as a teacher with “those inherent peculiarities, intellectual and emotional, which enable one human mind to reflect truth into others.” He co-authored two general textbooks: Comparative Anatomy (1936) and Chordate Anatomy (1939). He died in 1940; eight years later, MDI Bio Lab named its original laboratory building (built in the summer of 1921) in his honor.


Ulric Dahlgren (at left), a teacher and specialist in bioluminescence, takes the helm in 1920. With support from philanthropist George B. Dorr, Dahlgren moves the Laboratory to a new home on Mount Desert Island. The Laboratory’s equipment is packed up and shipped on its own boat, the Gadus, to Salisbury Cove, described as “a rich area for biological study in every field, vertebrate and invertebrate”.

Ulric Dahlgren

Ulric Dahlgren’s research centered on bioluminescence. He studied the development, physiology, behavioral uses, and evolution of light production in a range of animals, bacteria and marine life from sponges to jellyfish, worms, lobster, sea squirts, and fishes.

Born in Brooklyn, N.Y, in 1870, Dahlgren earned his BA (1894) and MS (1896) from Princeton University. He went on to teach there until 1939 (the same year he chaired the committee on fisheries exhibits at the New York World’s Fair).

Dahlgren wrote his “Principles of Histology” in 1908, the year of his first summer at the Harpswell Laboratory. Founding Director John Kingsley wrote that Dahlgren divided his time “between sailing and studying the histology of everything he could obtain.”

A colleague described Dahlgren as “one of [our] most outstanding teachers… a born biologist… equally at home with Maine coast fishermen, at a scientific session, or in the drawing room of a potential benefactor.”

Dahlgren became the Harpswell Laboratory’s Director in 1920. The next summer, he and Mt. Desert Island philanthropist George Dorr orchestrated the move to the shores of MDI’s Salisbury Cove.

The new, one-building laboratory was called the Weir Mitchell Station, after the famous neurologist and psychiatrist. The Dahlgren family moved into a farmhouse just to the west of the village school.

Dahlgren taught and researched at what became the MDI Bio Lab for the next 20 years, including six as Director (1920-1926) and nine as its President (1937-1946). The Dahlgren family lived in Bar Harbor until his death in 1946.

In recognition of his importance to the Laboratory’s early years, leaders named its first collecting boat after him in 1930, set up Dahlgren Fellowships in 1948 (aided by a grant from the American Philosophical Society), and, in 1947, named the recently purchased village schoolhouse “Dahlgren Hall”.

George B. Dorr

Born in 1853, George Dorr as a young man frequently visited Bar Harbor, where his parents built a home on the shore of Compass Harbor. In 1901, Harvard College President Charles W. Eliot (a summer resident of Northeast Harbor) asked Dorr to join a group of Mount Desert Island residents wanting to preserve its “tranquility”. Dorr joined the group, which included George Vanderbilt and John D. Rockefeller, Jr.

By 1912, their corporation had acquired over 5,000 acres on the island, by purchase and donation. In 1916, they designated a portion of the holdings the “Sieur de Monts National Monument,” which became Lafayette National Park in 1919 and in 1929, Acadia National Park.

Dorr wrote:

It struck me what a splendid and useful thing it would be if we could provide down here, in a spot so full of biologic interest and unsolved biologic problems, so rich in various beauty and locked around by the cool northern sea, a summer home, however simple, for men of science … to work…on a fresh field of life, bird or plant or animal and then go back invigorated, ready to do more valuable work the whole winter through in consequence of this climate boon and stimulating change.

Dorr was also a member of The Wild Gardens of Acadia (WGA, which owned land in Salisbury Cove). After Dorr received a letter from Ulric Dahlgren, an early leader of the original Harpswell Laboratory, about relocating it to MDI, the WGA leased its land to Dahlgren and his Harpswell colleagues in 1921. The original facility was called the Weir Mitchell Station, but it was renamed the Mount Desert Island Biological Laboratory in 1923. Dorr died in 1944.


Partners in science and life: Margaret R. and Warren H. Lewis (at left) develop new cell culture and other techniques to reveal basic truths about development, embryology, macrophages and much more.

Margaret R. and Warren H. Lewis

Margaret (Reed) Lewis and Warren Lewis collaborated as scientists for 55 years, initiating the beginnings of filmed microscopy, development of the first mammalian tissue cultures and the discovery of pinocytosis (the process during which cells take in fluids and small molecules). Their research expanded the theoretical knowledge of cell structure and function.

After graduating from Goucher College in 1901, Margaret Reed’s graduate work was guided by the future Nobelist Thomas Hunt Morgan. In 1905, at the Marine Biological Laboratory in Woods Hole, she met Warren Lewis, an anatomist and graduate of Johns Hopkins University. A leading investigator of early human development, he was instrumental in the discovery of embryonic induction — how one tissue influences the development of another.

In 1908, Margaret cultured bone marrow cells from guinea pigs, likely the first cell culture of mammalian cells. Married in 1910, they collaborated to fine-tune the new technology, a powerful tool for fundamental research in the emerging field of cell physiology.

Over their careers they worked here and at Johns Hopkins University, the Carnegie Institution and the Wistar Institute. Margaret’s work centered on white blood cells and chemical effects on cancer cells, while Warren focused on the differences between cancer and normal cells, cell division and motility, and pioneering work with microscopy and time-lapsed films.

In the early 1920s the Lewis family moved their summer research from the Harpswell Laboratory to the MDI Bio Lab. They lived in a seasonal cottage on the tip of Spruce Point through the 1960s. Their cottage is still owned and enjoyed by their descendants.

Warren was elected to the National Academy of Sciences in 1936 while serving as President of the MDI Bio Lab from 1932-1937. He died in 1964, followed by Margaret in 1970.


Kidney researchers Homer W. Smith, James A. Shannon and E. K. Marshall each begin a long relationship with the Laboratory, the foundation of its international reputation for discoveries in nephrology. Shannon would go on to serve as Director of the National Institutes of Health from 1955–1968.

Homer W. Smith

Homer Smith is one of the most revered figures in the MDI Bio Lab’s history, helping to establish its renown as a fount of discovery in renal physiology and recruiting many of its most highly regarded investigators.

Born in 1895, Smith received his doctorate from Johns Hopkins in 1921. He worked in multiple laboratories, making early studies in the development of invertebrates. In 1928, Smith became Physiology Director at New York University, where he remained until his retirement in 1961.

Starting In 1924, Smith became a summer fixture at the MDI Bio Lab. He compared the renal physiology among bony fish, sharks, skates, and rays. As with bony fishes, the shark kidney is unable to secrete excess salts. Smith proposed an “extrarenal” salt excretion site. His research framework still provides models for fish osmoregulation research.

At MDI Bio Lab, Smith also discovered that in contrast to mammals, whose nitrogenous waste is excreted by the kidneys, fish excrete nitrogenous waste across the gill epithelium. He also demonstrated that marine fish species had smaller glomerular filtration systems in their kidneys, consistent with reduced urine flows in marine fishes.

In 1942, Smith researched the pharmacology and action of nitrogen and sulfur mustards – work for the military on war gases that would be a precursor of modern chemotherapy. He served as President of the MDI Bio Lab from 1951-1960 and was a mentor to James Shannon, Bodil Schmidt-Nielsen, and Thomas Maren, substantial contributors to research and institutional development here through the mid-20th century.

An avowed agnostic, he enjoyed friendly debates with the pastor of the Eden Baptist Church, still standing next to the MDIBL. Smith wrote two world-renowned physiology textbooks, and a history of Western religions, entitled Man and His Gods (1952), with a foreword by Albert Einstein. Smith died in 1962.

E. K. Marshall

E.K. Marshall’s research focused on renal secretions and the influence of the adrenal gland on the kidneys.

Born in 1899, Marshall was a luminary in MDI Bio Lab’s history through the mid-20th century. He earned his doctorate in chemistry from Johns Hopkins in 1912 and later joined its faculty. In 1917, he received his M.D. before serving the Chemical Warfare Service during WWI. Marshall became Pharmacology Chair at Johns Hopkins in 1932, staying until his retirement in 1955.

In the 1920s, Marshall was a protagonist in a controversy about whether the vertebrate kidney nephron could add solutes and water to urine by secretion. His data supported secretion; others felt that urine excretion was the sum of filtration by kidney tubules and a bundle of capillaries called the glomerulus.

In 1926, Marshall’s literature review on fish renal anatomy revealed that the marine goosefish kidney lacked a glomerulus and would be a perfect model for urinary secretion studies. That winter, his colleague Warren Lewis noted that the tails of goosefish were a Maine delicacy and abundant in the waters off Mount Desert Island Biological Laboratory. Marshall came to the MDI Bio Lab that year.

Over the next two summers, he established that goosefish could produce urine containing injected phenol red dye, the first experimental demonstration of renal secretion.

In 1950, Marshall and J. Wendell Burger secured MDI Bio Lab’s first National Institutes of Health grant. He was elected to the National Academy of Sciences, and he served as MDI Bio Lab’s President from 1960-1964. What became the Marshall Laboratory was constructed in 1972.
Marshall’s continuing presence at MDIBL stimulated summer research of MDIBL investigators for generations, and his pharmaceutical company connections resulted in important funding during the lean years after WWII. He died in 1966.

“I was helping Dr. Shannon wash glassware… (when) I was absolutely overwhelmed by the totally unexpected arrival in the lab, first of Homer W. Smith and then E. K. Marshall. For me it was like being in the same room with the Father, Son and Holy Ghost.”

Roy Forster

Later himself a leader in renal physiology, on an early encounter on MDI
“I had come to a place where I could do research, learn from other scientists, and be stimulated by casual discussions through the free exchange of ideas, whether on the rocks outside the lab, at the cocktail parties or in the laboratories.”
Bodil Schmidt-Nielsen


Seeing deeper: cell development, membranes & transport

J. Wendell Burger begins work with spiny dogfish caught from Frenchman Bay; his later discovery of its rectal salt gland and salt glands in other vertebrates would shape some 50 years of research at MDI Bio Lab.

David A. Karnofsky brings innovative thinking on chemicals and cancer to MDI; his career would include leading the Memorial Sloan Kettering Institute’s chemotherapy research center. “All medical oncologists are his intellectual descendants,” one student says.

David A. Karnofsky

Karnofsy was a pioneering medical oncologist who helped to secure chemotherapy’s place in cancer treatment. The Karnofsky scale for assessing cancer intensity is still widely used around the world.

Born in 1914, Karnofsky received his M.D. from Stanford in 1940. He joined Homer Smith’s laboratory at the MDI Bio Lab in the summer of 1942. Under a wartime contract with the federal Office of Scientific Research and Development, he and Smith led research on the toxicology of nitrogen mustards and other military gases.

Their studies demonstrated that sublethal concentrations of the gases injured lymphatic tissue, spleen, bone marrow, and the epithelium of the small intestine. These studies were part of the basis for the post-war chemotherapeutic revolution in cancer treatment.

Karnofsky went on to become the Chief of the Division of Chemical Chemotherapy at what is now the Sloan Kettering Cancer Center. He continued to work at the MDI Bio Lab as well, studying the effects of various carcinogens on fertilized sand dollar eggs and embryos. These early toxicological studies would attract the next generation of toxicologists in subsequent decades.

Initially, the Karnofsky family stayed in one of the Cove Cottages which had been built in the early 1950s, but they soon built a private cottage on Sand Point Road.

In his honor, The American Society of Clinical Oncology created the Karnofsky Memorial Award for “innovated clinical research and developments that have changed the way oncologists think about the general practice of oncology.” In 1970, the MDI Bio Lab built the Karnofsky Laboratory, its first new laboratory in 30 years, thanks to donations from Karnofsky’s colleagues and friends. The Karnofsky Laboratory is still in use today.


Mentored by E.K. Marshall, Thomas H. Maren was recruited to the Laboratory. His basic discoveries about the enzyme carbonic anhydrase lead to the development of valuable diuretics and a powerful topical treatment for glaucoma.

Thomas H. Maren

The functions of carbonic anhydrase (CA) in marine and human physiology were a touchstone of Maren’s long research career, which stretched from basic biology to pharmaceutical applications. Mentored by other greats in kidney research, including E.K. Marshall, Maren was invited to MDI Bio Lab by Homer K. Smith in the summer of 1953.

Born in 1918, Maren earned his doctorate in medicine at Johns Hopkins in 1951.

Among his early discoveries was the effective oral carbonic anhydrase inhibitor, acetazolamide (Diamox), a diuretic which can treat swelling of the heart, glaucoma and other conditions. In 1955, Maren was recruited by the new University of Florida Medical School to form and chair its Department of Pharmacology, where he remained until his retirement in the early 1990s.

During decades of summer research at MDI Bio Lab, he and collaborating investigators delved into CA’s role in controlling the transport of solutes across particular epithelial cells that line organs and glands.

Maren could be very persuasive in recruiting research colleagues, which one undergraduate described as being “Marenated.” He was often consulted on administrative decisions and served on most important committees. The Maren family built a summer cottage on Bay View Drive, which is still inhabited by his stepchildren.

Maren made major contributions to various construction projects and fellowships undertaken on campus. His work with Merck Inc. in the development of the topical CA inhibitor, Trusopt, brough significant royalties; Maren and his family endowed Professorships at Princeton, Johns Hopkins, and the University of Florida. At the MDI Bio Lab, the Maren Foundation supported renovation of the Dining Hall, a substantial addition to Dahlgren Hall (Maren Auditorium), the planned renovation of Bowen Hall, and research grants to new investigators at the Laboratory for the past two decades. He died in 1999.


Homer Smith recruits Bodil Schmidt-Nielsen to the Laboratory, where she pursues kidney research with numerous animal models. She later becomes the Lab’s first permanent research scientist, President of the Board and the first female president of the American Physiological Society.

Bodil Schmidt-Nielsen

Bodil Schmidt-Nielsen was a wide-ranging comparative biologist and a pioneering woman in science; she also led the way for the MDI Bio Lab’s evolution into a year-round institution.

Born in Denmark in 1918, her parents were both distinguished physiologists – her father won the Nobel Prize. She started her career as an odontologist earning a doctorate in the field from the University of Copenhagen in 1941.

Work that she and her husband Knut did in the late 1940s on the water metabolism of kangaroo rats in southern Arizona brought them international recognition in comparative physiology. In 1952 Homer Smith recruited her to the MDI Bio Lab, the same year the couple took academic positions at Duke University.

During her first summer at the Bio Lab, she studied frog renal function, collaborating with Roy Forster to confirm E.K. Marshall’s earlier work showing that urea was secreted by frog renal tubules. This finding, supported by her work with kangaroo rats, was described as a “landmark” in renal urea transport.

Schmidt-Nielsen continued her amphibian renal studies here through the later 1950s, collaborating with Victor Murdaugh on harbor seal and beaver renal functions. In the early 1960s, she collaborated with Daniel Tosteson on studies of salt transport by the eel gill. These are just a few of the many colleagues and models she worked with.

Schmidt-Nielsen moved to Mt. Desert Island year-round in 1970, becoming the institution’s first year-round investigator. She would later become its president, as well as the first female president of the American Physiological Society.

She was instrumental in the origin of “Friends of the Laboratory” a group of non-scientists who eventually evolved into what is now the Board of Trustees. She died in 2015 at the age of 96.

“Leave your institutional baggage at the airport or the state line and prepare yourself for a place of rich history, lofty minds, biological camaraderie and unaffected research in a cove for science named Salsbury.”
Klaus W. Beyenbach
Renal physiologist


Physiology & its context: toxins, tissues & environment

Building on earlier work by Smith and Burger, Franklin H. Epstein’s research group (which included John N. Forrest, Jr., who later became a lab director) established the importance of the dogfish’s rectal gland for balancing salt and water content to regulate cell osmosis, a parallel to transport mechanisms in fish gills and human kidneys.

Franklin H. Epstein’s

Epstein was renowned for his insights on metabolism and nephrology. His research career was propelled by his work on the physiology, functions, and transport mechanisms of the shark’s rectal glands – a model that illuminated earlier kidney research and later as well.

Born in 1924, Epstein received his M.D. from Yale in 1947, and during his life held positions in a starry firmament of biomedical institutions: Boston University, Yale, Chief of Medicine at the Harvard’s Boston City Hospital and Chief of Medicine at Beth Israel Hospital, where he worked until his death in 2008.

Epstein first came to the MDI Bio Lab in the summer of 1968 to measure the activity of a transport enzyme, Na/K-Activated ATPase (NKA) in a variety of fish. He immediately showed that the dogfish rectal gland had the highest activity of NKA, and that the activity of NKA in the gills of bony fishes was higher in saltwater acclimated species, supporting Homer Smith’s model for bony fish osmoregulation, published 30 years before.

He and Bio Lab colleagues would go on to establish the shark’s rectal gland as central to shark osmoregulation, excreting salt compounds via mechanisms which mimic transport in the human kidney and fish gill.

Epstein served in various administrative roles, including President from 1985-1995. He amplified public relations and development efforts that had started a few years before, and he was instrumental in securing significant grants from the foundation community.

Epstein was awarded the John P. Peters Memorial Award by the American Society of Nephrology in 1985, and in 1993 the Presidential Medal of the American Society of Renal Biochemistry. In recognition for his research and administrative accomplishments at the MDI Bio Lab, the Laboratory renamed its Instrument Shed for Epstein.


Work on oil ingestion in herring gulls by William B. Kinter and others featured in Science, in 1978. Kinter, David Rall, David Miller and Helen Cserr identify biochemical sites of action of many environmental pollutants, including DDT, crude oil and heavy metals.

James L. Boyer validates dogfish and skate livers as useful models for human physiology and mechanisms that contribute to liver disease. He would lead the toxicity and genomics center for more than two decades, lead liver research at Yale and elsewhere, and create lifesaving techniques for liver surgery and after-care.

Laboratory Director David H. Evans wins a National Institute of Environmental Health Sciences award of $850K for the Laboratory’s Center for Membrane Toxicity Studies and the Comparative Toxicogenomics Database, catalyzing infrastructure investments and recruitment of new investigators.

“A zebrafish can make new nephrons, but humans can’t. We’re figuring out the signals an injured kidney releases, and how a kidney knows when and where to grow new nephrons... The fish do it all the time. They’re sitting there waiting to tell their secrets.”
Iain A. Drummond
Professor & Director, the Kathryn W. Davis Center for Regenerative Biology and Aging


A new vision: year-round research, expanded training & education

Courses and conferences boom on campus. The National Institutes of Health awards $5.5M to the Laboratory to lead what became the Maine INBRE, a statewide network of research and education institutions sharing expertise and infrastructure.

Laboratory Director John N. Forrest, Jr. stewards recruitment of year-round faculty and the adoption of new technologies: a bioinformatics unit, gene sequencer and video-conferencing.

State and federal funding allied with giving campaigns spark an era of winterization, renovation and construction. Efforts include a conference center, dormitory and dining facilities, and culminate in the construction of a 12,500 sq. ft. laboratory building named for philanthropists Wistar and Martha Morris.

The Kathryn W. Davis Center for Regenerative Biology and Aging is established in honor of the long-time benefactor, signaling a new research emphasis for the 21st century

“As we continue to grow, our core values of collaboration, integrity and scientific rigor guide us, but it is our unique culture and community spirit that sustain us and set us apart”
Hermann Haller
MDI Biological Laboratory President


Our growth: new labs, new models & a focus on aging & regeneration

Laboratory President Kevin Strange leads effort to win $13 million NIH award to designate the Laboratory as a Center for Biomedical Research Excellence (COBRE), supporting four new, year-round research groups in the Davis Center.

New investigators leverage non-marine models for comparative biology that are easily adapted to transgenic modification, bioinformatic analysis and 3D microscopy: C. elegans roundworms, zebrafish, killifish and axolotl salamanders.

Long-time summer investigator Hermann Haller takes the reins as President. He focuses on collaboration and enterprise, cultivating new partnerships with research institutions in Maine and abroad.

Aric N. Rogers and Jarod A. Rollins demonstrate dietary methods to increase C. elegans roundworm lifespan by 500%; Iain A. Drummond and Hermann Haller adapt zebrafish kidney tubules for organoid development; Prayag Murawala and James W. Godwin discover new pathways for limb and organ regeneration.

Into the future

We are building on a remarkable foundation.

The MDI Bio Lab’s model of rigorous science in a small, informal environment has proven itself. Today’s researchers are continuing in the tradition, even as they create new tools and knowledge that will accelerate our timeline of discovery.

Learn more about the ways in which you can support our groundbreaking work.


*MDI Bio Lab Director Emeritus David H. Evans, Ph.D., is the author of Marine Physiology Down East: The Story of the Mt. Desert Island Biological Laboratory (Springer, 2015)