Embryo Project Encyclopedia

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.

This embryology image is a pencil sketch by Nicolaas Hartsoeker, published as part of his 1694 French-language paper entitled Essai de Dioptrique, a semi-speculative work describing the sorts of new scientific observations that could be done using magnifying lenses. Dioptrique was published in Paris by the publishing house of Jean Anisson. The image depicts a curled up infant-like human, now referred to as a homunculus, inside the head of a sperm cell. This sketch is important to embryology because it is one of the most illustrative examples of preformationism, a theory of generation stating that each future member of any given species exists, fully formed though miniscule, within the gametic cells (sperm or eggs) of its parents. This theory was popular among naturalists in the eighteenth century.

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. This sketch was only a minor part of his first publication, Essai de Dioptrique (1694), which dealt primarily with the use of optical lenses in science. In subsequent years the sketch became iconic of the theory of embryological development known now as preformationism. Hartsoeker himself was a vocal adherent of spermist preformationism and is often cited as the originator of the idea.

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. Preformationism was a widely-held theory by Enlightenment-era scientists, but by the early 1800s, most scientists had abandoned it, in part because higher magnification in microscopes enabled them to see the very earliest stages of embryos as small collections of cells. Prior to preformationism, naturalists who studied embryo development favored the theory of spontaneous generation in lower animals, such as flies, which appeared to arise from manure. In higher animals, however, scientists used the theory of epigenesis put forth by Aristotle, who said that maternal and paternal fluids came together in the uterus and solidified during early gestation into a fetus. Preformationism was the first theory of generation and development that applied to all organisms in the plant and animal kingdoms.

On March 28, 1978, in Stump v. Sparkman, hereafter Stump, the United States Supreme Court held, in a five-to-three decision, that judges have absolute immunity from lawsuits involving any harm their judicial decisions cause. Linda Sparkman, who was unknowingly sterilized when she was fifteen years old in 1971, sued Harold Stump, the county circuit court judge who signed the petition to allow Sparkman’s mother to have her sterilized. Sparkman’s mother stated to Stump that she wanted her daughter sterilized because of Sparkman’s alleged mental deficiencies and sexual promiscuity. Sparkman argued that Stump violated her Fourteenth Amendment rights to due process because nobody informed her about the nature of the procedure and because Stump did not perform typical court proceedings. Stump argued that, because he was acting within his role as a judge, the doctrine of judicial immunity prevented his liability from lawsuit. Stump strengthened the impunity with which judges can act, including acts found to be unconstitutional, regardless of any rights upon which such actions may infringe.

In 1990, the United States Congress passed the Americans with Disabilities Act, or the ADA, which prohibits discrimination against people with disabilities by employers, governments, or public accommodations. Following gains made during the civil rights movements of the 1900s, people with disabilities sought similar anti-discrimination legislation. The ADA was the culmination of decades of protest and advocacy from the disability rights movement. After the ADA, federal law protected people with an impairment that limited major life functions like sight or mobility from discrimination. The ADA changed the lives of millions of Americans with disabilities by expanding the opportunities they had to work, travel, and participate in their communities legally protected from discrimination.

In United States v. Georgia, the United States Supreme Court held, in a unanimous decision, that the rights protected under the Americans with Disabilities Act, or the ADA, extended to inmates held in state prisons. The Court also abolished sovereign immunity in cases where the Eighth Amendment is involved. The case came about as a result of Tony Goodman, a paraplegic man in a Georgia state prison, who attempted to sue the state under Title II of the ADA. The state of Georgia argued that they were immune to civil suits based on sovereign immunity under the Eleventh Amendment that holds that Congress cannot pass laws that allow non-consenting states to be sued by their people, except for specific circumstances. The US federal government interceded on Goodman's behalf, with the case then being taken up by the Supreme Court. US v. Georgia partially determined the extent to which the ADA covers disabled Americans, improved the situation of disabled individuals in state prison systems, and further eroded the sovereign immunity claimed by states in cases where ADA violations are alleged.

In the 1999 case Olmstead v. L.C., hereafter Olmstead, the United States Supreme Court held in a six to three decision that the forced segregation of people based on disability violated the Americans with Disabilities Act. Two women with mental and intellectual disabilities, Lois Curtis and Elaine Wilson, referred to as L.C. and E.W. in case documents, sued the state of Georgia and Tommy Olmstead, the Commissioner of Georgia who headed the Department of Human Resources, for alleged violations of the Americans with Disabilities Act. The two women each voluntarily admitted themselves to treatment in the state-run Georgia Regional Hospital in Atlanta, Georgia, in 1990. After doctors cleared Curtis and Wilson for transfer into a community-based health setting with non-disabled people, the hospital denied them treatment in a community-based setting due to the financial costs of such treatment and the lack of space. Olmstead protected the rights of people with disabilities outlined in the Americans with Disabilities Act by finding the unjustified segregation of disabled people unconstitutional.

In 1975, the United States Congress passed the Individuals with Disabilities Education Act, referred to as the IDEA, which codified the right of all American children to a free and appropriate public education regardless of disability status. The IDEA requires all public schools that accept federal funds to provide education that meets the needs of students with disabilities at the public expense. Prior to IDEA, many students with disabilities went without any educational opportunities, and many faced confinement in institutions. The IDEA enshrined the right to education for children with disabilities, allowing millions of children to learn in a public-school classroom by setting guidelines for accessibility and the instruction of students with disabilities in American public schools.

In 1972, the United States District Court for the Eastern District of Pennsylvania decided the case of Pennsylvania Association for Retarded Citizens (PARC) v. Commonwealth of Pennsylvania, hereafter PARC v. Pennsylvania. The court ruled that the state could not deny an individual's right to equal access to education based on an intellectual or developmental disability status. PARC brought the case against the state of Pennsylvania on behalf of fourteen families with intellectually disabled children who were unable to access to public schools based on their child’s disability. PARC challenged state laws that permitted schools to deny education to children who do not reach the mental age of five, or the average intelligence of people aged five, by the time they begin first grade. Both sides settled following the testimony of expert witnesses on PARC's behalf, and the US District Court approved the consent decree. PARC v. Pennsylvania was one of the first cases to establish that people born with an intellectual disability should have the same access to education as the rest of the population.