Mycotrophy — xiii — Contents 



Limitation of endophyte — Digestion of endophyte — 

 Mycothalli in fern gametophytes — Mycothalli in lyco- 

 POD gametophytes — Mycorrhizomes in ferns — Mycor- 



RHIZOMES in orchids MyCOCARYOPSES AND INFECTION OF 



aerial organs 91 



Lecture VIII 



Mycodomatia:- Significance of the term — Psilotum — 



Cycads — PoDOCARPus — Casuarina — Myrica — Alnus — 



Polygonum — Raphanus — Tribulus — Legumes — Ailan- 



THUS — Ceanothus — Elaeagnus — Hippophae — Coriaria 



— Eucalyptus — Daucus — Ericads — Solanum — Melam- 



PYRUM OrOBANCHE — CoMPOSITES — JUNCUS MOLINIA 



— Cyperus — Asparagus — Allium — Orchids . . 103 



Lecture IX 

 Structure of Mycorrhizae:- The kinds of mycorrhizae — My- 

 corrhizal compared with non-mycorrhizal roots — Exter- 

 nal form — Pseudomycorrhizae — The colours of mycor- 

 rhizae — The exterior surface — The mycorrhizal apex — 

 Renewed growth — Ectotrophic vs. endotrophic — Ecto- 

 trophic mycorrhizae — Endotrophic mycorrhizae — Pel- 

 OTON mycorrhizae — Vesicular-arbuscular mycorrhizae 



— Arbuscles — Ericaceous mycorrhizae — Coralloid my- 

 corrhizae — Tuberous mycorrhizae — Outer cortex and 



PASSAGE cells WaLL TUBULES HaRTIG NET ThE STELE 



116 



Lecture X 

 Obligate Symbiosis:- Fungi and trees — Ecological influences 



— Special cases — Fungi and herbs — Obligatism and 

 NUTRITION — The ericads — The problem of Calluna — 

 Other Ericaceae — The orchids — Germination of orchid 

 SEED — Necessity of orchid fungus — Degeneration of 

 orchid fungus — Hydrolysis of starch — Sugars and asym- 

 biotic germination — Fungus supplies sugar — Impotence 

 of unaided small seeds — Carbon supply to embryo — Oblig- 

 atism IN LOWER PLANTS SUMMARY 136 



Lecture XI 

 Theories of Mycotrophy:- Contrasted concepts — Parasitism 



— Curbed pathogens — Schools of mycotrophism — Mycor- 



