CONTENTS XI 



3. SOREDIA 



PAGE 



A. Structure and Origin of Soredia . . 141 



a. Scattered soredia 

 d. Isidial soredia 

 c. Soredia as buds 



B. SORALIA -144 



a. Form and occurrence of soralia 

 l). Position of soraliferous lobes 

 c. Deep-seated soralia 



C. Dispersal and Germination of Soredia . . 147 



D. Evolution of Soredia . .... 148 



4. ISIDIA 



A. Form and Structure of Isidia . . . 149 



B. Origin AND Function of Isidia . . 151 



VI. HYMENOLICHENS 



A. Affinity WITH OTHER Plants . 152 



B. Structure OF Thallus . • iS3 



C. Sporiferous Tissues ... .154 



CHAPTER IV 



REPRODUCTION 



I. REPRODUCTION BY ASCOSPORES 



A. Historical Survey ... . 155 



B Forms of Reproductive Organs . . . .156 



a. Apothecia 

 d. Perithecia 



C. Development OF Reproductive Organs . 159 



I. DISCOLICHENS 



a. Carpogonia of gelatinous lichens 



6. Carpogonia of non-gelatinous lichens 



c. General summary 



d. Hypothecium and paraphyses 



e. Variations in apothecial development 



aa. Parmeliae 

 id. Pertusariae 

 cc. Graphideae 

 dd. Cladoniae 



