A Father of Embryology
Karl Ernst von Baer, one of the founders of modern embryology, was born in Piibe, Estonia on this date in 1792. Baer discovered the mammalian ovum (egg cell) in 1826, and was also the first to describe the blastula and notochord. In his studies of embryonic development in animals, Baer noticed that embryos of different animals were similar in the early stages of development, taking on differential characteristics in later stages. His two-volume History of the Development of Animals lays out his "germ layer theory" – the concept that embryos in the early stages of development divide into two or three germ layers that can go on to form different organs and tissues. Baer, a critic of Charles Darwin, made germ-layer theory the basis of his own general evolutionary theory. He died on November 28, 1876.
Copyright Aetna InteliHealth, Inc., 2012. All rights reserved.