Loeb, Jacques (1859–1924)

German physiologist. His controversial research on caterpillars in 1888 demonstrated that animals, like plants, possess similar mechanistic physiological responses (tropisms) to environmental stimuli. In 1899, he discovered artificial parthenogenesis in sea urchin eggs. His studies on protein chemistry (1918–24) revealed that proteins can react as acids or bases. His philosophy of psychological and physiological tropisms is summarized in his most-read book, The Mechanistic Conception of Life (1912).

Loeb was born in Mayen, Germany. He taught and performed research in Germany (1886–91). Frustrated by Bismarck's oppressive regime, Loeb moved to the USA to teach at Bryn Mawr College in Pennsylvania (1891–92). He moved to the University of Chicago (1892–1902), and the University of California, Berkeley (1902–10), before becoming a physiology professor at the Rockefeller Institute (1910–24).