Structure, etc., of Epiphegus Virginiatia. 385 



irregular lumps of chromatin massed along fine linin threads. 

 In the centre is a large spherical densely stained nucleolus 

 (Fig. 6). 



In somewhat older flowers the ovules have assumed their 

 definite form. They are attached to the placenta by long 

 curving funiculi. The funiculus consists of rows of elon- 

 gated faintly stained cells, with a large pale nucleus and 

 very small nucleolus. The seed-coats have appeared. At 

 first a single one is present, composed of a double row of 

 rectangular nucleated cells, surrounding the embryo sac. 

 Other ovules show both seed-coats, being surrounded by 

 four rows of cells. Their anatropal state is now evident, the 

 micropyle occurring next the funiculus. 



Down the centre of the ovule extends the embryo sac. It 

 is comparatively short at first, but later becomes almost as 

 long as the ovule itself. It is a great elongated cell, boutided 

 by a definite wall and filled with densely stained cytoplasm. 

 In the youngest stage a single very large nucleus is present. 

 It possesses a relatively enormous nucleolus that is spherical, 

 and very densely stained chromatin is seen in masses stream- 

 ing through the clear nuclear cavity. Later this nucleus 

 divides in two, and the two nuclei move apart toward the 

 poles of the cell (Plate XXXI, Fig. 7). When they lie at 

 the poles, each is seen surrounded by an aggregation of cyto- 

 plasm, while a considerable vacuole has appeared in the mid- 

 dle of the elongating embryo sac, or macrospore cell. A 

 shrunken thread-like protoplasmic connection is retained 

 between the two separated masses (Fig. 8). 



Division of each of these two cells next occurs, the axes 

 of the two spindles being perpendicular to each other. The 

 upper or micropylar spindle (Fig. 9) lies at right angles to 

 the long axis of the ovule. The lower distal spindle lies 

 parallel to the axis of the ovule. These spindles are long 

 and tapering in outline, apparently ending in pointed apices. 

 So in the four-celled stage, the two pairs of nuclei lie at 

 right angles to each other. Later the two upper nuclei turn 



