meiosis was discovered and described for the first time in sea urchin eggs in 1876, by oscar hertwig. it was described again in 1883, at the level of chromosomes, by van beneden in "ascaris" eggs. the "significance of meiosis for reproduction and inheritance", however, was first described in 1890 by weismann, who noted that two cell divisions were necessary to transform one diploid cell into four haploid cells if the number of chromosomes had to be maintained. thus the work of the earlier cytologists laid the ground for weismann, who turned his mind to the consequences for evolution, which was an aspect the cytologists had not addressed. all this took place before the work of mendel had been rediscovered.