[115] Hertwig had a year before expressed a similar view in regard to the equivalency of the blastomeres.
[116] A view advanced by Pflüger.
[117] The evidence to show that more than four and certainly more than eight such groups that come from a single egg can produce a pluteus is, I think, insufficient, and the result improbable.
[118] Driesch’s figures seem to show, nevertheless, that the archenterons are proportionately too large.
[119] These may be pieces that were cut obliquely, as Driesch suggests, so that they contain a part of the archenteric region.
[120] Driesch, Hertwig, Roux, Weismann, Barfurth. For review see Driesch (’95).
[121] Bunting (’94) also found that isolated blastomeres of hydractinia make whole embryos.
[122] If the yolk of the dividing egg is partially withdrawn without disturbing the blastomeres, the form of the cleavage may be altered, but a normal whole embryo develops over the smaller yolk sphere.
[123] We offered as a possible explanation in this case that the egg had been cut in two symmetrically with reference to the eccentric nucleus.
[124] These experiments have been quite fully described in my book on The Development of the Frog’s Egg.