. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. Archegonium of the same, 300 diam. a, origin of the archegonium; the shaded vertical row of cells constitutes the rudiment of the organ ; b, archegonium immediately before impregnation. 61. Second period.—Fructification of the ar- chegonia. In the greater number of archego- nia, development ceases at the point above described. In those in which the germ-cell has received the influences necessary for its fructification, this last-named body enlarges rapidly, and very soon divides by a slightly Fig. Archegonium of th
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. Archegonium of the same, 300 diam. a, origin of the archegonium; the shaded vertical row of cells constitutes the rudiment of the organ ; b, archegonium immediately before impregnation. 61. Second period.—Fructification of the ar- chegonia. In the greater number of archego- nia, development ceases at the point above described. In those in which the germ-cell has received the influences necessary for its fructification, this last-named body enlarges rapidly, and very soon divides by a slightly Fig. Archegonium of the same immediately after impregna- tion. The germ-cell has divided by an oblique septum. oblique septum, which is followed by a number of others, alternately inclined in opposite directions. This results in an egg-shaped body, perfectly separable from the surround- ing tissues. The last-formed summit-cell now divides by a septum which is inclined not in the opposite direction, but in a direction at right angles to that of its predecessor. This is followed by a second in the same relation ; that by a third, and so on continuously. The cylindrical rudiment now consists of four columns of cells, each of which is divided symmetrically by a vertical septum, into an external trapezoid and an internal three-sided cell. The former again divides, first, by a ver- tical, then by a horizontal septum, both of them perpendicular to the surface of the rudi- ment, which now consists of four central cel- lular columns, which are enclosed in eight others formed of trapezoidal cells. These last divide by vertical septa, alternately paral- lel and perpendicular to the external surface, by means of which the rudiment gradually thickens. This process goes on much more actively at the lower than at the upper or middle portion, in consequence of which it becomes club-shaped ; its swollen base being embedded in the parenchyma of the stem of the parent, and causes absorption of its cells. The cells
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