January 17, 1834, German biologistWeissmanBorn in Frankfurt, Germany. In 1892, Weissmann proposed the germplasm continuity theory, which distinguished germplasm and constitution for the first time in the history of biology, and emphasized the stability and continuity of germplasm. It provided a basic idea for the later establishment of chromosome inheritance theory and the development of gene theory, which had a huge impact on the development of biology and genetics.