330 



MORPHOLOGY. 



into a great many nuclei in a mass of protoijlasm, and cell walls 

 are formed separating them into cells. This mass of cells is the 

 endosper?)!, and it surrounds the 

 embryo. It is the mature female 

 prothallium, belated in its growth 

 in the angiosperms, usually de- 

 veloping only when fertilization 

 takes place, and its use has been 

 assured. 



660. Seed. — As the embryo 



Mature embryo s^c {ynunii prn- 

 tliallium) of liliiim. ///, niicropylar 

 end; .S', synergids ; E. c^j.; ; /';/, 

 jiul.ir nuclei; Ant, anli[iudals. 

 (Easter lily.) 



S-v,-^< 





Tie ^g4 



Section throLigli tutclln Tiid m pLi part of embryo 

 sac of cotton at lirnt; of cnti.nnce of pi lien tube. 'A', 

 e<i;:;; .S', Rynerjj;ids; /', pollen tube willi sperm cell in 

 thu end. (Diiggar.) 



