CHAPTER IV

REPRODUCTION

I. REPRODUCTION BY ASCOSPORES

A. HISTORICAL SURVEY 155

B. FORMS OF REPRODUCTIVE ORGANS 156 _a._ Apothecia _b._ Perithecia

C. DEVELOPMENT OF REPRODUCTIVE ORGANS 159

1. DISCOLICHENS

_a._ Carpogonia of gelatinous lichens _b._ Carpogonia of non-gelatinous lichens _c._ General summary _d._ Hypothecium and paraphyses _e._ Variations in apothecial development _aa._ Parmeliae _bb._ Pertusariae _cc._ Graphideae _dd._ Cladoniae

2. PYRENOLICHENS

_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 _f._ 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

G. GENERAL SURVEY 205 _a._ Sexual or asexual _b._ Comparison with fungi _c._ Influence of symbiosis _d._ Value in diagnosis