Ziegler (’98) has also made some observations on the egg of this same ctenophore, that bear directly on some of the questions here raised. His study of the cleavage shows that the micromeres arise from the part of the egg that is opposite the pole at which the first cleavage furrow appears--the animal pole. Fischel’s results have shown that the paddles and the sense organs arise from these micromeres, for, if the latter are displaced the former are also. Ziegler performed the experiment of cutting off that part of an egg (which has just begun to divide) lying opposite the region in which the first furrow has appeared. In this way there was removed from the unsegmented egg the part from which the micromeres develop. Ziegler found that the micromeres still arise, and that from such pieces larvæ develop that have _eight_ rows of paddles and _four_ endodermal sacs. In one case two of the sacs were smaller than the others; in another case one of the four was very much smaller than the rest. In another operation a large piece was cut from the egg, leaving a small nucleated piece that divided into two blastomeres of unequal size. An embryo developed from this small piece with four endodermal sacs, and only _four_ well-developed rows of paddles. The four rows of paddles that were lacking were represented by two groups of a few plates each. Ziegler gives a different interpretation of these results from that which Driesch and Morgan have offered. He interprets the last experiment, in which after the operation the piece divided into two unequal parts, and only four rows of paddles appeared, as meaning that the development of these organs on the smaller part is suppressed on account of the small size of the part. If the part had been still smaller all trace of the missing paddles might disappear, as he thinks was the case in certain experiments of Driesch and Morgan. There can be, I think, little doubt that if a piece is small enough, the result would follow as Ziegler supposes. It does not seem probable, however, that the pieces were really below the lower limit in the experiments of Driesch and Morgan, since the smaller blastomere was in one case as large as the whole piece (_i.e._ as both blastomeres taken together) in one of Ziegler’s experiments.