 Wilhelm Roux adopted much the same approach as Weismann’s and so, at first, did Hans Driesch. Yet their experiments ultimately led to new approaches and revised interpretations of what was at issue with epigenesist and preformationist accounts of development (Maienschein 1991b and Weber 2022). In 1888, Roux published results of his experiments on frog eggs. Working on the assumption of a mosaic type preformationism, Roux was persuaded that starting from the very first cell division, each cell would be different because it was already predetermined to be different.