Part 4

„ 3. Cleistocarpeæ 195

„ 4. Stegocarpeæ 195

DIVISION III. PTERIDOPHYTA 198

Class 1. FILICINÆ 205

Sub-Class 1. Filices 205

Family 1. Eusporangiatæ 210

„ 2. Leptosporangiatæ 212

Sub-Class 2. Hydropterideæ 215

Class 2. EQUISETINÆ (HORSETAILS) 221

Sub-Class 1. Isosporous Equisetinæ 221

„ 2. Heterosporous Equisetinæ 225

Class 3. LYCOPODINÆ (CLUB MOSSES) 226

Sub-Class 1. Lycopodieæ 226

„ 2. Selaginelleæ 228

TRANSITION FROM THE CRYPTOGAMS TO THE PHANEROGAMS 234

Asexual Generation of the Cormophytes 234

Sexual Generation; Fertilisation 243

DIVISION IV. GYMNOSPERMÆ 251

Class 1. CYCADEÆ (CYCADS) 252

„ 2. CONIFERÆ (PINE-TREES) 255

Family 1. Taxoideæ 259

„ 2. Pinoideæ 262

Class 3. GNETEÆ 270

Fossil Gymnosperms 271

DIVISION V. ANGIOSPERMÆ 273

Class 1. MONOCOTYLEDONES 274

Family 1. Helobieæ 278

„ 2. Glumifloræ 283