A miniature individual imagined by early biologists to be present in the head of the sperm cell.
Dwarf with no deformity or abnormality and all parts of the body proportionate.
A dwarf with no deformity or abnormality other than small size.
A dwarf in whom the body parts develop in their normal proportions.
Diminutive of the Tatin homo, meaning “man”; a term adopted by embryologists in the 18th century to conjure up the idea of a very small human being. In this period, doctors were engaged in an argument that had its roots in a dichotomy that went back beyond Rome to ancient Greek science. On one side, the preformationists argued that embryology must represent an unfolding of preexisting structure; in other words, a tiny being complete in all its essentials, a homunculus, lay in reproductive organs concealed from view or from the magnifying power of then available microscopes. Two sites for the homunculus were disputed: The ovists expected to find it in the female egg, while the spermatists thought it more likely to be in the male sperm. On the other side of the argument was a group called the epigeneticists headed by Pierre Maupertuis, an 18th-century French scientist, who disliked the idea of a homunculus and thought it more likely that embryos contained coded instructions rather than preformed parts.
It is easy to see epigeneticists as the unbiased empirical scientists and the preformationists as pseudoscientists blinkered by theological prejudice, trying to uphold the centuries-old belief that St. Anne became pregnant with her daughter the Virgin Mary by a sexless conception. But these things are seldom as simple as they seem, and according to the Harvard science professor, Stephen Jay Gould, the preformationists were the ones who were actually putting forward a view of science closer to that of our own by requiring a material cause for all phenomena. Given the science of the day, how could they believe that a complex human body could develop out of nothing? In retrospect, the epigeneticist view of causality was far too close to that of vitalism the idea that there was an external, nonmaterial force that could impose a design upon the unformed egg.