Further studies of the prospective fates of blastomeres at the 32-cell stage of Xenopus laevis embryos.

Each blastomere in the marginal zone of Xenopus laevis embryos at the 32-cell stage was stained with Nile blue sulphate. Only specimens with the typical arrangement of blastomeres of morulae of this species were used, and special care was taken to prevent the dye from spreading to neighbouring cells and to determine the extent of stained areas. The prospective fate of each blastomere was studied and a new fate-map of the 32-cell embryo was drawn by tracing the movement of stain during the course of further development.