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Displaying 1041 - 1050 of 1172 items.

Spermism

By Cera R. Lawrence

Spermism was one of two models of preformationism, a theory of embryo generation prevalent in the late seventeenth through the end of the eighteenth century. Spermist preformationism was the belief that offspring develop from a tiny fully-formed fetus contained within the head of a sperm cell. This model developed slightly later than the opposing ovist model because sperm cells were not seen under the microscope until about 1677.

Format: Articles

Subject: Theories

Ovism

By Cera R. Lawrence

Ovism was one of two models of preformationism, a theory of generation prevalent in the late seventeenth through the end of the eighteenth century. Contrary to the competing theory of epigenesis (gradual emergence of form), preformationism held that the unborn offspring existed fully formed in the eggs or sperm of its parents prior to conception. The ovist model held that the maternal egg was the location of this preformed embryo, while the other preformationism model known as spermism preferred the paternal germ cell, as the name implies.

Format: Articles

Subject: Theories

Preformationism in the Enlightenment

By Cera R. Lawrence

Preformationism was a theory of embryological development used in the late seventeenth through the late eighteenth centuries. This theory held that the generation of offspring occurs as a result of an unfolding and growth of preformed parts. There were two competing models of preformationism: the ovism model, in which the location of these preformed parts prior to gestation was the maternal egg, and the spermism model, in which a preformed individual or homunculus was thought to exist in the head of each sperm.

Format: Articles

Subject: Theories

John Spangler Nicholas (1895-1963)

By Ellen M. Dupont

John Spangler Nicholas, an American biologist, was born on 10 March 1895 in Allegheny, Pennsylvania. He was the only child of Elizabeth Ellen Spangler, a teacher, and Samuel Trauger Nicholas, a Lutheran minister. Nicholas held myriad administrative positions throughout his life and his contributions to biology spanned several sub-disciplines, but his most notable accomplishments were in the field of embryology.

Format: Articles

Subject: People

Marie Stopes International

By Ellen M. DuPont

Marie Stopes International (MSI) is a not-for-profit organization based in the United Kingdom that promotes reproductive and sexual health. It grew from one small clinic, founded in North London in 1921, into an international provider of reproductive health care and information that operates in almost forty countries. The Mothers' Clinic, from which it grew, was created in the hopes of expanding couples' reproductive rights, and the modern organization continues to work toward the same goal today.

Format: Articles

Subject: Organizations, Reproduction

The Mothers' Clinic

By Ellen M. DuPont

The Mothers' Clinic for Constructive Birth Control was established on 17 March 1921. The first family planning clinic ever established in Great Britain, it was co-founded by Marie Charlotte Carmichael Stopes and her husband Humphrey Verdon Roe at Number 61, Marlborough Road in Holloway, North London. The Mothers' Clinic was one of the highlights of Stopes's extensive career as a proponent of available birth control and women's sexual equality.

Format: Articles

Subject: Organizations, Reproduction

Henry Havelock Ellis (1859-1939)

By Ellen M. DuPont

Henry Havelock Ellis was born on 2 February 1859 at Croydon in Surrey, England, to Susannah Wheatley Ellis and Edward Peppen Ellis, a sea captain. A psychologist, essayist, and physician, he is best known for his contributions to the study of human sexuality and his support of sex education and women's rights. Ellis 's work catalyzed the revolution against repressive Victorian views of sexuality.

Format: Articles

Subject: People

Marie Charlotte Carmichael Stopes (1880-1958)

By Ellen M. DuPont

Marie Charlotte Carmichael Stopes was born in Edinburgh, Scotland, on 15 October 1880 to Charlotte Carmichael Stopes, a suffragist, and Henry Stopes, an archaeologist and anthropologist. A paleobotanist best known for her social activism in the area of sexuality, Stopes was a pioneer in the fight to gain sexual equality for women. Her activism took many forms including writing books and pamphlets, giving public appearances, serving on panels, and, most famously, co-founding the first birth control clinic in the United Kingdom.

Format: Articles

Subject: People, Ethics, Reproduction

Amniocentesis

By Katherine Brind'Amour

Amniocentesis is a test used for prenatal diagnosis of inherited diseases, Rh incompatibility, neural tube defects, and lung maturity. Normally performed during the second trimester of a pregnancy, this invasive procedure allows the detection of health problems in the fetus as early as fifteen weeks gestation. Although amniocentesis does carry some significant risks, the medical community commonly accepts it as a safe and useful procedure.

Format: Articles

Subject: Technologies, Reproduction

Summerfield v. Superior Court [Brief] (1985)

By Brock Heathcotte

Arizona joined the majority of states that recognized wrongful death claims on behalf of a viable fetus, regardless of whether the child was born alive or died in the womb by expanding the definition of "person" to include a viable fetus.

Format: Articles

Subject: Legal, Reproduction