386 



PLANT MORPHOLOGY 



synergids are generally interpreted as potential eggs normally incapable 

 of being fertilized. The three nuclei at the chalazal end of the embryo 

 sac, which is the one opposite the micropylar end, are usually organized 

 as small naked or walled cells called antipodals. The antipodals, some- 

 times ephemeral, are usually somewhat persistent, rarely giving rise later 



ow 



Fig. 331. Ovule of Anemone patens with mature embryo sac, X200; ow, ovary wall; oc, 

 ovary cavity; st, stalk of ovule; i, integument; m, micropyle; es, embryo sac; s, synergid; e, 

 egg;/, fusion nucleus; a, antipodal cell. 



to an extensive tissue. The antipodals are said to be nutritive in function 

 and probably represent vegetative cells of the female gametophyte in 

 various stages of disappearance. 



Variations in Embryo -sac Development. The development of the ordi- 

 nary type of embryo sac is characterized by two important features: 



