Ernst Heinrich Haeckel (1834-1919), German biologist and philosopher who popularized
Charles Darwin's work in Germany. He was a professor of comparative anatomy. He noticed that "ontogeny recapitulates phylogeny", which is not entirely true. Haeckel was one of the first to consider psychology as a branch of physiology. He also proposed the term "ecology".
His observations on the link between
ontogeny and philogeny
? have been named as the "recapitulation law". As Haeckel's effort to prove the law was provably misguided and inaccurate, he became a favorite target of
creationists, as a "proof" against
evolution.
See http://www.ucmp.berkeley.edu/history/haeckel.html for a biography.