THE GYMNOSPERMAE : CONIFERALES AND TAXALES 683 



PINUS 



TAXUS CYCAS ANGIOSPERM 



MICROSPORE 



FIRST 



PROTHALLIAL 



CELL 



TUBE CELL 



FIRST PROTHALLIAL 

 CELL 



SECOND 

 PROTHALLIAL CELL 



TUBE CELL 



TWO PROTHALLIAL 

 CELLS 



ANTHERIDIAL 

 CELL 



TUBE CELL 



TWO PROTHALLIAL 

 CELLS 



STALK CELL 

 BODY CELL 

 TUBE CELL 



TWO PROTHALLIAL 

 CELLS 



STALK CELL 

 MALE GAMETES 



TUBE CELL 



MICROSPORE 



FIRST PROTHALLIAL 

 V ^^CELL 



TUBE CELL 



ONE PROTHALLIAL 

 CELL 



ANTHERIDIAL 

 CELL 



OR 



GENERATIVE 

 CELL 



TUBE CELL- 



E PROTHALLIAL 

 CELL 



STALK CELL 



BODY CELL 



TUBE CELL 



ONE PROTHALLIAL 

 CELL 



STALK CELL 



MALE GAMETES 

 (ANTHER 



OZOIDS) 

 MALE NUCLEI 



■TUBE CELL 



Fig. 683. — A comparison of the male gametophytes oi Pinus, Taxus, Cycas and an 

 Angiosperm showing varying degrees of reduction. 



