ANGIOSPERMS. 



GYMNOSPERMS. 



Microspore 



I 



Prothallial cell 



(usually absent) 



Generative cell 



Maepospore 



Synergidie 

 Antipodal cells 



-Definitive nucleus 

 Oospiiere 



Endosferm 



Oospore 

 Sporophyte 



= spore-forming generation. 



He ma I 



Antipodal cells = Rudiments of a primary 



prothallium or gametophyte (female pro- 

 thallium of Macrospore, Hetcnjsporous 

 Pteridophyta). 



Synerg'idsB = Rudiments of lormer Arche- 



gonia, or Oogonia of Pteridophyta. 



Endosperm is the result of double fer- 

 tilisation and = a secondary prothal- 

 lium. 



Prothallial cell in Microspore (when 

 present) = Rudiment of Male prothal- 



lium homologous with Male prothallium 

 in Microspore of Marsilea (Hetero- 



sporous Pteridophyta). 



Generative cell = Antherozooids of lower 



types. 



Microspore 



Prothallial cell 



Generative cell 



Maerr 

 I 



Prothi 

 I 



Arche 



Oosp} 



Oospore 



I 



Embryonal cells 



I 



Sporophyte 



/!' iiiar!,-f : 



Prothallium in ]Macrospoie = Female 

 thallium produced in Macrospo 



Marsilea (Heterosporous Pteridophyt 



Arehegonia = Oogonia of either 



sporous or Heterosporous Pteridopliy 



Generative cell = Antherozooids of 



types. 



In Ginkyo'and Cytadt.r [Zamia) Anthen 

 are produced in the Microspore in tht 

 of non-motile generative cells. 



