. The cell; outlines of general anatomy and physiology. Cells; Anatomy; Physiology; Cells; Anatomy; Physiology. THE VITAL PHENOMENA OF THE CELL 241 rest, they reappear, and division proceeds as usual. If, however, the substances are allowed to act npon the eggs for from 10 to 20 minutes, a still greater disturbance is produced, resulting in many cases in a very peculiar and, in its way, typical course of the division process. Not only are the pole radiations completely destroyed, but the nuclear segments become gradually transformed into the vesi- cular resting condition of the nucleus (Fig. 1
. The cell; outlines of general anatomy and physiology. Cells; Anatomy; Physiology; Cells; Anatomy; Physiology. THE VITAL PHENOMENA OF THE CELL 241 rest, they reappear, and division proceeds as usual. If, however, the substances are allowed to act npon the eggs for from 10 to 20 minutes, a still greater disturbance is produced, resulting in many cases in a very peculiar and, in its way, typical course of the division process. Not only are the pole radiations completely destroyed, but the nuclear segments become gradually transformed into the vesi- cular resting condition of the nucleus (Fig. 129 JL). This constitutes the starting point of a new but considerably modified process of division (0. and R. Hertwig VI. 38).. Fig. 129.—Nuclei of eggs of Strongijloaentrotm which, one and a half hours after the act of fertilisation has occurred, have been placed in "025 per cent, solution of quinine sulphate, where they remained for twenty minutes. A Nuclear figure of an egg, which was killed one hour after it was removed from the quinine solution ; B nuclear figure of an egg, killed somewhat later; C nuclear figure of an egg, killed two hours after it was removed from the quinine sulphate solution. Instead of two radiations, four develop immediately upon the surface of the nuclear vesicle (Fig. 129 B, in which one radiation is obscured). If treated with quinine, these soon become sharply defined; when, however, chloral is used, they remain permanently faint, and confined to the immediate neighbourhood of the nucleus. The nuclear membrane next becomes dissolved ; five spindles de- velop between the four poles, and upon these the nuclear seg- ments distribute themselves equatorially, thus producing a cha- racteristic figure (Fig. 129 G). The nuclear segments then move towards the four poles, and form the basis for four vesicular nuclei, which separate from one another and travel towards the surface of the yolk. The egg then begins, by means of two cross furrows, to beco
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