Embryo Project Encyclopedia Articles

Jacques Loeb developed procedures to make embryos from unfertilized sea urchin eggs in 1899. Loeb called the procedures "artificial parthenogenesis," and he introduced them and his results in "On the Nature of the Process of Fertilization and the Artificial Production of Norma Larvae (Plutei) from the Unfertilized Eggs of the Sea Urchin" in an 1899 issue of The American Journal of Physiology. In 1900 Loeb elaborated on his experiments. Following those publications, however, he discovered he had used inaccurately labeled salts and redid his experiments to determine the correct amount of salts needed for artificial parthenogenesis.

Jacques Loeb broadened and corrected his earlier claims concerning artificial parthenogenesis in sea urchins in a series of experiments in 1900. He published these findings, "Further Experiments on Artificial Parthenogenesis and the Nature of The Process of Fertilization," in a 1900 issue of The American Journal of Physiology. His new results amended those from earlier experiments he summarized in 1899's "On the Nature of the Process of Fertilization and the Artificial Production of Norma Larvae (Plutei) from the Unfertilized Eggs of the Sea Urchin." Loeb's 1899 results were tainted by improperly prepared salts used in his experiments. Loeb's 1900 results corrected those of 1899 and led to more refined study of artificial parthenogenesis, the human-caused development of unfertilized eggs.