X CONTENTS 



PACE 



Chapter X. Coniferophytes — Ginkgoales 184 



Extinct members 184 



Ginkgo 186 



Life-history 186 



Phylogeny 215 



Chapter XI. Coniferophytes — ^Coniferales 217 



Taxonomy 226 



Geographic distribution 231 



The sporophyte — vegetative 234 



Chapter XII. Coniferophytes — Coniferales {continued) .... 275 



The sporophyte — reproductive 275 



Chapter XIII. Coniferophytes — Coniferales {continued) . . . 306 



The male gametophyte 306 



Chapter XIV. Coniferophytes — Coniferales {continued) . . . 321 



The female gametophyte 321 



Chapter XV. Coniferophytes — Coniferales {continued) . . . .331 



Fertilization 331 



Chapter XVI. Coniferophytes — Coniferales {continued) . 342 



The embryo 342 



Chapter XVII. Coniferophytes — Gnetales — Ephedra . • 361 



Geographic distribution 362 



The sporophyte — vegetative 364 



The sporophyte — reproductive 368 



Fertilization 377 



Embryogeny 381 



Chapter XVIII. Coniferophytes — Gnetales — Welwitschia . 384 



Geographic distribution 3S4 



The sporophyte — vegetative 385 



The sporophyte — reproductive 392 



The male gametophyte 400 



The female gametophyte 401 



Fertilization 404 



Embryogeny 404 



Chapter XIX. Coniferophytes — Gnetales — Gnetum 408 



The sporophyte — vegetative 408 



The sporophyte — reproductive ... 412 



