Chapter VII: Phylogeny

I. GENERAL STATEMENT

A. ORIGIN OF LICHENS 272

B. ALGAL ANCESTORS 273

C. FUNGAL ANCESTORS 273
_a._ Basidiolichens
_b._ Ascolichens

II. THE REPRODUCTIVE ORGANS

A. THEORIES OF DESCENT IN ASCOLICHENS 273

B. RELATION OF LICHENS TO FUNGI 275
_a._ Pyrenocarpineae
_b._ Coniocarpineae
_c._ Graphidineae
_d._ Cyclocarpineae

III. THE THALLUS

A. GENERAL OUTLINE OF DEVELOPMENT OF THALLUS 281
_a._ Preliminary considerations
_b._ Course of evolution in Hymenolichens
_c._ Course of evolution in Ascolichens

B. COMPARATIVE ANTIQUITY OF ALGAL SYMBIONTS 282

C. EVOLUTION OF PHYCOLICHENS 283
_a._ Gloeolichens
_b._ Ephebaceae and Collemaceae
_c._ Pyrenidiaceae
_d._ Heppiaceae and Pannariaceae
_e._ Peltigeraceae and Stictaceae

D. EVOLUTION OF ARCHILICHENS 287
_a._ Thallus of Pyrenocarpineae
_b._ Thallus of Coniocarpineae
_c._ Thallus of Graphidineae
_d._ Thallus of Cyclocarpineae
_AA._ LECIDEALES
_aa._ Coenogoniaceae
_bb._ Lecideaceae and Gyrophoraceae
_cc._ Cladoniaceae
1. Origin of Cladonia
2. Evolution of the primary thallus
3. Evolution of the secondary thallus
4. Course of podetial development
5. Variation in Cladonia
6. Causes of variation
7. Podetial development and spore-dissemination
8. Pilophorus, Stereocaulon and Argopsis
_BB._ LECANORALES
_aa._ Course of Development
_bb._ Lecanoraceae
_cc._ Parmeliaceae
_dd._ Usneaceae
_ee._ Physciaceae

CHAPTER VIII
SYSTEMATIC

I. CLASSIFICATION

A. WORK OF SUCCESSIVE SYSTEMATISTS 304
_a._ Dillenius and Linnaeus
_b._ Acharius
_c._ Schaerer
_d._ Massalongo and Koerber
_e._ Nylander
_f._ Müller-Argau
_g._ Reinke
_h._ Zahlbruckner

B. FAMILIES AND GENERA OF ASCOLICHENS 311

C. HYMENOLICHENS 342

II. NUMBER AND DISTRIBUTION

1. ESTIMATES OF NUMBER

2. GEOGRAPHICAL DISTRIBUTION

A. GENERAL SURVEY 343

B. LICHENS OF POLAR REGIONS 345

C. LICHENS OF THE TEMPERATE ZONES 348

D. LICHENS OF TROPICAL REGIONS 352

III. FOSSIL LICHENS