Animalculists

17th-century biologists who thought that a spermatozoon contained a preformed grown animal in microscopic form and that embryo development consisted merely of increase in size and change in consistency of the organs whereby they ceased to be transparent. Contrary to the ovists, the animalculists viewed the egg as the source of nourishment for the spermatozoon. One of the most prominent animalculists was A. van Leeuwenhoek. Animalculists supported preformation.