Structure, etc., of Epipliegus Virginiana, 389 



dicular to the preceding division, so that two smaller cells lie 

 side by side beyond the oblique wall. There is no indication 

 of any differentiation into special regions such as is usually 

 shown in normal embryos. The whole mass remains spher- 

 ical and undifferentiated. 



The upper cell of the two-celled stage has proceeded 

 slowly with its division, while the lower cell has been thus 

 active. It divides twice, to form two equal cells above, and 

 a small flattened lenticular cell below. The middle of these 

 three cells then divides in two in the other direction, so that 

 there appear two smaller cells lying side by side (Fig. 16). 

 These four cells form a kind of elongated neck rising above 

 the spherical mass below. In the latest stages observed, I 

 hi\e never seen any further differentiation in this structure, 

 which is evidently a rather degraded suspensor. 



In the mature ovule or seed, that is ready for discharge, 

 the embryo appears one-third the distance below the micro- 

 pyle. The albumen cells have increased to eight or more 

 rows. They have enlarged greatly, especially the outer cells, 

 and have become fainter in staining capacity. The cyto- 

 plasm is reduced in amount, the nucleus is rather pale and 

 faint-looking. These cells are cubical usually, and well 

 filled with starch grains. A considerable cellulose thicken- 

 ing develops along the regular outer row of albumen cells, 

 and forms some distance down thin division walls. Of the 

 seed-coats, only the outer row of cells is now functional. 

 The remaining cells lie in shrunken narrow strands outside 

 the albumen. This outermost row of cells is enormously 

 enlarged. Each contains little cytoplasm, a pale nucleus and 

 vacuolated nucleolus, and numerous large starch grains. 

 There is a great development of a dense clear shining wall- 

 thickening, that looks like cork. In surface view, this 

 appears like a lattice-work, of long parallel bands joined by 

 occasional short cross-bars. In section, this thickening is 

 seen to develop entirely in the side walls of the cells, as a 

 broadly lenticular mass. The outer and inner walls are quite 

 unthickened. 



