CONTENTS 



2. Spore-producing members 



Microsporangium 

 Megasporangium 



3. Gametophytes . 



Female gametophyte 

 Male gametophyte 

 Fertilization . 



4. Embryo 



Proembryo 

 Suspensor and embryo 



5. History and distribution 



6. Relationship to other gymnosperms 

 List of genera 

 Literature cited 



Chapter VIII. Gnetales 



1. Vegetative organs 



Vascular anatomy 

 Leaf 



2. Spore-producing members 



Microsporangium 

 Megasporangium 



3. Gametophytes 



Female gametophyte 

 Male gametophyte 

 Fertilization . 



4. Embryo 



5. History and distribution 



6. Relationships . 

 Literature cited 



319 



319 

 321 



329 

 329 

 335 

 344 



346 

 346 

 348 



349 



350 



353 



353 



363 



364 

 366 



369 

 370 

 371 

 376 



384 

 384 

 389 

 391 



393 

 402 



402 



404 



Chapter IX. Evolutionary tendencies among gymnosperms 406 



Phylogeny 407 



Vascular anatomy 411 



Leaf 412 



Strobilus 413 



