теодор керкринг (1638 - 1693)
Theodor Kerckring (Dutch: Thomas Theodor Kerckring) or Dirk Kerckring was a Dutch physician and anatomist, a member of the Royal Society of London.
Kerckring received his MD degree in Leiden and came to Amsterdam. Here, thanks to his acquaintance with the famous anatomist Ruysch, he took up the study of anatomy, in the field of which he made many remarkable discoveries.
In his book Spicilegium Anatomicum, Theodore Kerckring described and illustrated many anatomical deformities and diseases. Observations also included public health risks. He was one of the first to study the development of the human embryo and the fetal bone system. Kerckring's most important and significant contribution was his discovery that the fetal skeleton develops by the transformation of membrane and cartilage into bone.