We must, therefore, conclude that artificial membrane formation induces development but that it leaves the egg in a sickly condition in which the very processes leading to cell division bring about its destruction; that if it is given time it can recover from this condition and that the treatment with the hypertonic solution also brings about this recovery rapidly and reliably. Herlant[101] suggested that the corrective effect of the hypertonic solution consisted in the proper development of the astrospheres required for cell division. According to this author mere membrane formation does not lead to the formation of sufficiently large astrospheres and hence cell division may remain impossible.[102] The writer has no _a priori_ objection to this suggestion which agrees with earlier observations by Morgan except that it is at present difficult to harmonize it with all the facts. Why should it be possible to replace the treatment with the hypertonic solution by a suspension of the oxidations in the egg for three hours while we know that lack of oxygen suppresses the formation of astrospheres in the fertilized eggs? What becomes of the astrospheres if the treatment with the hypertonic solution precedes the membrane formation by a number of hours or a day (which is possible as we shall see), and why do they not induce cell division, if Herlant’s idea is correct? Nevertheless the suggestion of Herlant deserves to be taken into serious consideration. [101] Herlant, M., _Arch. de Biol._, 1913, xxviii., 505. [102] It is also important to remember that the formation of astrospheres after mere membrane formation occurs considerably more slowly than if the egg has also received a treatment with a hypertonic solution.