VI 11 



CONTENTS 



Chapter III. Cycadales 



1. Vegetative organs . 



Vascular anatomy 



Leaf 



Root 



2. Spore-producing members 



Microsporangium 

 M egasporangium 



3. Gametophytes 



Female gametophyte 

 Male gametophyte 

 Fertilization . 



4. Embryo 



5. History and distribution 



6. Relationship to other gymnosperms 

 Literature cited 



91 



93 

 93 



108 

 112 



114 

 114 

 121 



132 

 132 



139 

 1-48 



150 

 156 

 157 

 158 



Chapter IV. Cordaitales 



1. Vegetative organs 



Vascular anatomy 



Leaf 



Root 



2. Spore-producing members 



Strobilus 



Microsporganium 



Megasporangium 



3. Gametophytes 



4. History and distribution 



5. Relationship to other gymnosperms 

 Literature cited 



163 



164 



i6s 

 168 



171 



172 

 172 

 172 

 174 

 178 

 180 

 180 

 183 



Chapter V. Ginkgoales 



I. Vegetative organs . 

 Vascular anatomy 

 Leaf 



185 



185 

 187 

 189 



