SPERM ATOPHVTA 



385 



G H 



Fig. 330. Megasporogenesis and early development of the embryo sac of Anemone patens, 

 X200. A, young ovule with megaspore mother cell; B, first meiotic division; C, comple- 

 tion of first division; D, linear tetrad of megaspores; E, functional megaspore enlarging; F, 

 division of mega.spore nucleus; G, 2-nucleate embryo sac; H, 4-nucleate embryo sac. 

 (From preparations supplied by Dr. George H. Conant.) 



times remain distinct (Fig. 331). The three nuclei left at the micropylar 

 end of the embryo sac become organized as naked cells, forming the egg 

 apparatus. Of these, one is the egg and the two others are synergids. 

 Ordinarily the egg lies between the synergids and slightly exceeds them in 

 size; its nucleus is farther from the micropyle than their nuclei are. 

 Usually the three cells forming the egg apparatus are pyriform. The 



