Search

Displaying 26 - 50 of 65 items.

Sir D'Arcy Wentworth Thompson (1860-1948)

Known by many for his wide-reaching interests and keen thinking, D'Arcy Wentworth Thompson was one of Britain's leading scientific academics in the first few decades of the twentieth century. A prodigious author, Thompson published some 300 papers, books, and articles in the biological sciences, classics, oceanography, and mathematics. He was a famous lecturer and conversationalist-a true "scholar-naturalist," as his daughter wrote in her biography of her father.

Format: Articles

Subject: People

Joseph Bolivar DeLee (1869–1942)

Joseph Bolivar DeLee was an obstetrician in the US between the nineteenth and twentieth centuries who advocated for the specialized teaching of medical students in the field of obstetrics to address problems occurring during pregnancy. He claimed obstetricians maintained a wider skillset than midwives, and founded the Chicago Lying-In Hospital to provide affordable obstetric care to women in Chicago, Illinois.

Format: Articles

Subject: People

Emil Kraepelin (1856–1926)

Emil Kraepelin was a physician who studied people with mental illness in the late nineteenth and early twentieth centuries in modern-day Germany. Kraepelin's examination and description of the symptoms and outcomes of mental illness formed the basis for his classification of psychiatric disorders into two main groups, dementia praecox, now called schizophrenia, and manic-depressive psychosis, now called bipolar disorder. He was one of the first physicians to suggest that those researching mental illness should gain scientific knowledge only through close observation and description.

Format: Articles

Subject: People, Disorders

Karl Wilhelm Theodor Richard von Hertwig (1850-1937)

Karl Wilhelm Theodor Richard von Hertwig is an important figure in the history of embryology for his contributions of artificial hybridization of sea urchin eggs and the formulation of his coelom theory. He was born 23 September 1850 in Friedelberg, Germany, to Elise Trapp and Carl Hertwig. Richard and his older brother Oscar began their studies at Jena under the direction of Ernst Haeckel from 1868 to 1871. In 1872 Hertwig became a lecturer in zoology at Jena while Oscar lectured in anatomy and embryology.

Format: Articles

Subject: People

Charles Darwin's Theory of Pangenesis

In 1868 in England, Charles Darwin proposed his pangenesis theory to describe the units of inheritance between parents and offspring and the processes by which those units control development in offspring. Darwin coined the concept of gemmules, which he said referred to hypothesized minute particles of inheritance thrown off by all cells of the body. The theory suggested that an organism's environment could modify the gemmules in any parts of the body, and that these modified gemmules would congregate in the reproductive organs of parents to be passed on to their offspring.

Format: Articles

Subject: Theories

Antoni van Leeuwenhoek (1632-1723)

Antoni van Leeuwenhoek was born in Delft, the Netherlands, on 24 October 1632 to Margriet Jacobsdochter van den Berch and Philips Thooniszoon, both of whom were middle-class artisans. He attended grammar school in Warmond, and then temporarily moved to Benthuizen to live with relatives. Eventually Leeuwenhoek left for Amsterdam to work as a cloth merchant's apprentice. Returning to Delft, he married Barbara de Mey on 29 July 1654, and worked as a shopkeeper. The marriage resulted in five children, only one of whom, Maria, outlived Leeuwenhoek.

Format: Articles

Subject: People

William Harvey (1578-1657)

Renowned physician and scientist William Harvey is best known for his accurate description of how blood circulates through the body. While his published work on the circulation of blood is considered the most important of his academic life, Harvey also made significant contributions to embryology with the publication of his book Exercitationes de Generatione Animalium in 1651. In this book he established several theories that would set the stage for modern embryology and addressed many embryological issues including conception, embryogenesis, and spontaneous generation.

Format: Articles

Subject: People

George Washington Corner (1889-1981)

As the third director of the Carnegie Institute of Washington s Department of Embryology, George Washington Corner made a number of contributions to the life sciences as well as to administration. Corner was born on 12 December 1889 in Baltimore, Maryland, near the newly established Johns Hopkins University. Although Corner was not exposed to science much in school at a young age, he developed an early appreciation for science through conversations with his father about geography and by looking through the family's National Geographic magazines.

Format: Articles

Subject: People

August Friedrich Leopold Weismann (1834-1914)

August Friedrich Leopold Weismann studied how the traits of organisms developed and evolved in a variety of organisms, mostly insects and aquatic animals, in Germany in the late nineteenth and early twentieth centuries. Weismann proposed the theory of the continuity of germ-plasm, a theory of heredity. Weismann postulated that germ-plasm was the hereditary material in cells, and parents transmitted to their offspring only the germ-plasm present in germ-cells (sperm and egg cells) rather than somatic or body cells.

Format: Articles

Subject: People

“Miscarriage of Medicine: The Growth of Catholic Hospitals and the Threat to Reproductive Health Care” (2013), by Lois Uttley, Sheila Reynertson, Larraine Kenny, and Louise Melling

In 2013, Lois Uttley, Sheila Reynertson, Larraine Kenny, and Louise Melling published “Miscarriage of Medicine: The Growth of Catholic Hospitals and the Threat to Reproductive Health Care,” in which they analyzed the growth of Catholic hospitals in the United States from 2001 to 2011 and the impact those hospitals had on reproductive health care. In the US, Catholic hospitals are required to abide by the US Catholic Church's Ethical Guidelines for Health Care Providers, also called the Directives.

Format: Articles

Subject: Publications

Curt Jacob Stern (1902-1981)

Curt Jacob Stern studied radiation and chromosomes in humans and fruit flies in the United States during the twentieth century. He researched the mechanisms of inheritance and of mitosis, or the process in which the chromosomes in the nucleus of a single cell, called the parent cell, split into identical sets and yield two cells, called daughter cells. Stern worked on the Drosophila melanogaster fruit fly, and he provided early evidence that chromosomes exchange genetic material during cellular reproduction.

Format: Articles

Subject: People

Nicolaas Hartsoeker (1656-1725)

Nicolaas Hartsoeker, a Dutch astronomer, optics manufacturer, and naturalist, was born 26 March 1656 in Gouda, Netherlands, and died 10 December 1725. His mother was Anna van der Mey and his father was Christiaan Hartsoeker, a prominent evangelical minister. His major contribution to embryology was his observations of human sperm cells, which he claimed to be the first to see under a microscope. His sketch of the homunculus, a tiny preformed human he believed to exist in the head of spermatazoa, is his lasting scientific legacy in the field of embryology.

Format: Articles

Subject: People

Stazione Zoologica Anton Dohrn, Naples, Italy

The Stazione Zoologica Anton Dohrn (Anton Dohrn Zoological Station) is a public research institute focusing on biology and biodiversity. Hereafter called the Station, it was founded in Naples, Italy, in 1872 by Anton Dohrn. The type of research conducted at the Station has varied since it was created, though initial research focused on embryology. At the turn of the twentieth century, researchers at the Station established the sea urchin (Echinoidea) as a model organism for embryological research.

Format: Articles

Subject: Organizations, People, Places

“Sex Limited Inheritance in Drosophila” (1910), by Thomas Hunt Morgan

In 1910, Thomas Hunt Morgan performed an experiment at Columbia University, in New York City, New York, that helped identify the role chromosomes play in heredity. That year, Morgan was breeding Drosophila, or fruit flies. After observing thousands of fruit fly offspring with red eyes, he obtained one that had white eyes. Morgan began breeding the white-eyed mutant fly and found that in one generation of flies, the trait was only present in males.

Format: Articles

Subject: Experiments, Publications

Muriel Wheldale Onslow (1880-1932)

Muriel Wheldale Onslow studied flowers in England with genetic and biochemical techniques in the early twentieth century. Working with geneticist William Bateson, Onslow used Mendelian principles and biochemical analysis together to understand the inheritance of flower colors at the beginning of the twentieth century. Onslow's study of snapdragons, or Antirrhinum majus, resulted in her description of epistasis, a phenomenon in which the phenotypic effect of one gene is influenced by one or more other genes. She discovered several biochemicals related to color formation.

Format: Articles

Subject: People

Franz Julius Keibel (1861-1929)

Franz Keibel studied the embryos of humans and other animals in Europe at the turn of the twentieth century. He lived and worked in several different parts of Germany and France. Keibel drew illustrations of embryos in many stages of development. Keibel used these illustrations, which he and others in the scientific community called normal plates, to describe the development of organisms in several species of vertebrates.

Format: Articles

Subject: People

St. George Jackson Mivart (1827-1900)

St. George Jackson Mivart studied animals and worked in England during the nineteenth century. He also proposed a theory of organismal development that he called individuation, and he critiqued Charles Darwin's argument for evolution by natural selection. His work on prosimians, a group of primates excluding apes and monkeys, helped scientists better investigate the Primate group.

Format: Articles

Subject: People

Paul Kammerer's Experiments on Sea-squirts in the Early Twentieth Century

In the early twentieth century, Paul Kammerer, a zoologist working at the Vivarium in Vienna, Austria, experimented on sea-squirts (Ciona intestinalis). Kammerer claimed that results from his experiments demonstrated that organisms could transmit characteristics that they had acquired in their lifetimes to their offspring. Kammerer conducted breeding experiments on sea-squirts and other organisms at a time when Charles Darwin's 1859 theory of evolution lacked evidence to explain how offspring inherited traits from their parents.

Format: Articles

Subject: Experiments, Organisms