Showing posts with label oceanography. Show all posts
Showing posts with label oceanography. Show all posts

Sunday, February 10, 2013

Victor Hensen


Christian Andreas Victor Hensen was born on February 10, 1835 in Schleswig, which is now part of Germany. His father Hans Hensen was the director of a school for the deaf in Schleswig and his mother, Henriette, was the daughter of the court physician. Hensen graduated from the cathedral school in Schleswig in 1845 and the grammar school at Glukstat, in Holstein in 1854. He studied medicine at the universities of Wurzburg, Berlin, and Kiel, passing his final examination in 1858. In 1859 he completed his thesis on epilepsy and urinary secretions. After finishing his doctorate he worked as a prosector at the University of Kiel. He was appointed professor of physiology in 1871 and he remained there until 1911. In 1867 he became a member of the Prussian House of Representatives. From 1878 he was the director of the institute of physiology at Kiel. In addition to his work on physiology, Henesen was also an oceanographer and lead many oceanographic expeditions.

Hensen's work was involved with many fields of science including physiology, oceanography, and chemistry. His physiological work included describing the structures of the inner ear. These studies led to the discovery of the Hensen duct, Hensen cells and Hensen stripe. These structures and cells are part of the cochlea, the snail shell shaped structure in the inner ear that is responsible for sensing sound waves. Hensen was also able to extract glycogen from the liver and there was a priority dispute about this between him and Claude Bernard. Now it is known that Hensen verified Bernard's work.

Hensen is most remembered for his coining of the word plankton to describe the microscopic sea organisms that form the basis of the ocean's food chain. These organisms include drifting animals, plants, archea, algae, and bacteria. The term plankton describes an ecological niche rather than a specific type of organism. Because they depend on sunlight they are found in greater numbers on the surface of bodies of water. They are found in oceans and lakes and are an important food source for fish and whales. Hensen developed methods of collecting and studying plankton that are still used today.

Hensen died on April 5, 1924.


References:

Press and Communication Services, University of Kiel; "Famous Scholars from Kiel: Victor Hensen"; Retrieved from www.uni-kiel.de

Raica, M.; "A Short Story of Victor Hensen and a Cell of the Inner Ear"; Romanian Journal of Morphology and Embryology (2012)53:855-857

Victor Hensen Wikipedia Entry

Sunday, July 29, 2012

William Beebe

Charles William Beebe was born on July 29, 1877 in Brooklyn, New York. His father, Charles Beebe, was a paper dealer and was frequently away from home. When Beebe was 2 the family moved to East Orange, New Jersey, away from New York City, which his mother, Henrietta Younglove Beebe, found stifling. The family often took the train into New York City to visit the American Museum of Natural History where they attended lectures. Young Beebe often explored the wilderness around his family home and was an avid collector of animals and insects that he found there. Beebe attended East Orange High School and in 1896 he entered Columbia University in New York City. At Columbia he studied under Henry Osborn. Beebe did not complete his degree at Columbia, finishing all the classes neccessary for a degree except mathematics, and instead he took a job as the assistant curator of ornithology at the new New York Zoological Park, what is now the Bronx Zoo.

As assistant curator Beebe's job was to breed and rear the birds in the zoo's collection. Beebe wanted to give his avian charges the most space possible and so he proposed a "flying cage" the size of a football field, which was built, but only at half the size of his proposal. In 1901 he was part of expedition to Nova Scotia to collect marine animals for the zoo and the following year he was promoted to be a full curator. In 1903 Beebe took an expedition to the Florida keys. Suffering from a throat infection and it was thought that the expedition to the tropics would be beneficial. The expedition fueled Beebe's interest in the wildlife found in the tropics and was the first of many that he would make during his life.

Over the next several years Beebe made many expeditions to collect birds traveling to Mexico, British Guiana, Trinidad, Venezuela, and in 1909 he traveled to the far east on a 17 month expedition, visiting 21 countries and gathering material for a monograph on pheasants. Although the manuscript was completed by 1914, Beebe was fastidious in his desire to have excellent illustrations of the birds. Because of this and the outbreak of World War I the first volume (of four) was not published for 4 more years. In 1915 Beebe traveled to Brazil to obtain more birds for the zoo. The expedition was an important turning point for Beebe as his focus began to change from simply ornithology to studying jungle ecosystems.

After briefly serving as an aviation instructor for the American war effort, in 1918 Beebe began a series of expeditions including the Galapagos islands, the Sargasso Sea, and Haiti. Over the years Beebe's focus widened from just ornithology to study other areas of biology and oceanography. One of Beebe's most important contributions to the study of birds was the theory that the ancestors of modern birds had passed through a stage he referred to as the "tetraptrex" stage where the ancestral birds had four wings on both their fore and hind limbs. This theory was later verified by fossil evidence.

Beebe is probably most famous for his part in the development of the bathysphere. At the time deep sea diving was only possible in heavy and not very movable diving suits. Working with engineer Otis Barton, Beebe developed the bathysphere, an unpowered, spherical shell that was lowered from a ship by means of a cable and ocean life could be viewed through the quartz windows embedded in the side of the sphere. Using the bathysphere they had developed, Beebe and Otis set a world record on a half mile dive in 1934 of off Nonsuch Island in Bermuda. Beebe retired in 1952 at the age of 75.

Beebe died on June 4, 1962 in Simla, India and was buried in Trinidad.


References:

Crandall, Lee S.; "In Memoriam: William Charles Beebe"; The Auk (1964)81:36-42

Gould, Carol Grant; The Remarkable Life of William Beebe: Explorer and Naturalist; Island Press; 2004

Hines, Catherine L.; "William Charles Beebe"; 2000

William Beebe Wikipedia Entry