PLATE III. 



Figs. 20, 21. Four sections of an embryo-sac of A. sirnflex containing an egtj 

 apparatus and two free nuclei which were in process of division, a, b, 

 X 120 ; c, d, X 250 : c, the egg ; d, one of the synergids. 



Figs. 22, 23. The dividing free nuclei. x 650. x starch granule (?) at one pole 

 of the nuclear spindle. 



Fig. 24, a-c. Three sections of an embryo-sac of A. simplex in which the egg 

 apparatus was lateral in position ; </, outline of the egg apparatus. 

 The endosperm {en. ) is beginning to form. x 90. 



Fig. 25. Young endosperm-cells from the sac shown in fig. 24. x 250. 



Fig. 26. Transverse section of the egg apparatus of A. simplex; 0, egg ; sy.^ 

 synergids. x 250. 



Fig. 27. Basal part of the same, showing two of the four large free nuclei. x 250. 



Figs. 28, 29. Young nuceilus and embryo-sac of A. modestuni. The embryo-sac 

 [e.s.) has entirely destroyed the apical tissue of the nuceilus. In 28 

 there is apparently a second embryo-sac {e.s.) (?). x 90. 



