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A TEXTBOOK OF THEORETICAL BOTANY 



AXIAL FILAMENT 



TETRASPORANGIUM 



STALK CELL 



PERICENTRAL 



CELL 



COVER CELL 



B 



Fig. 158. — Polysiphonia sp. A, Tetrasporangial branch, 

 showing development of tetrasporangia from pericentral 

 cells. B, Surface view of an older branch showing 

 mature tetrasporangia. (After Smith.) 



Fig. 159. — Life-cycle of 

 Polysiphonia. 



Tetrasporic 



Plant' 



Mole Plant 



Female Plant 



Carpospore 



Female 

 Nucleus 



Spermatium 



