xii CONTENTS 



2. PYRENOLICHENS 



PAGE 



a. Development of the perithecium 



b. Formation of carpogonia 



D. APOGAMOUS REPRODUCTION . . . . . 174 



E. DISCUSSION OF LICHEN REPRODUCTION . . ' , 177 



a. The Trichogyne 



b. The Ascogonium 



F. FINAL STAGES OF APOTHECIAL DEVELOPMENT . 181 



a. Open or closed apothecia 



b. Emergence of ascocarp 



G. LICHEN ASCI AND SPORES . . . . 184 



a. Historical 



b. Development of the ascus 



c. Development of the spores 



d. Spore germination 



e. Multinucleate spores 

 / Polaribilocular spores 



II. SECONDARY SPORES 



A. REPRODUCTION BY OIDIA 189 



B. REPRODUCTION BY CONIDIA 190 



a. Rare instances of conidial formation 



b. Comparison with Hyphomycetes 



C. CAMPYLIDIUM AND ORTHIDIUM .... 191 



III. SPERMOGONIA OR PYCNIDIA 



A. HISTORICAL ACCOUNT OF SPERMOGONIA . . 192 



B. SPERMOGONIA AS MALE ORGANS . . 193 



C. OCCURRENCE AND DISTRIBUTION .... 193 



a. Relation to thallus and apothecia 



b. Form and size 



c. Colour 



D. STRUCTURE . 196 



a. Origin and growth 



b. Form and types of spermatiophores 



c. Periphyses and sterile filaments 



E. SPERMATIA OR PYCNIDIOSPORES ... ... 201 



a. Origin and form 



b. Size and structure 



c. Germination 



d. Variation in pycnidia 



F. PYCNIDIA WITH MACROSPORES 204 



