Lecture II — 19 — Occurrence of Mycorrhizae 



most part, would not be suspected of harbouring endophytes although 

 it is true that a fungus has been reported from a Sphagnum capsule ; 

 the Andreales are not mentioned; and but one report comes to us of 

 the higher mosses. Servattz (1913) stated that white filaments of a 

 fungus (the size of Streptothrix) formed dense intertangled masses 

 which grew well on agaricized peptone bouillion, a fungus which 

 seemed to be an Oospora. This organism exerted a particularly ac- 

 tivating action on Phascum cuspidatum, and in culture the moss plants 

 and mycelium made normal growth when together whereas without 

 the mycelium the moss developed only a protonema. This favourable 

 action was negated later when the fungus covered over the gelose and 

 gained ascendancy over the moss. 



Fungal Symbiosis with Pteridophytes : — Fungal symbiosis 

 seems to occur commonly with Pteridophytes and certain species, 

 especially of the OphiogJossaceae, have been studied intensively. On 

 the other hand, the families of Matoniaceae, Hymenophyllaceae and 

 Schisaeaceae have never been examined for symbiotic fungi, so far as 

 literature records ; while many species in the remaining families are 

 yet tO' be investigated. It is scarcely to be expected that the Parkeri- 

 aceae, Marsiliaceae and Salviniaceae should harbour mycorrhizal endo- 

 phytes since these plants are aquatics; and we find that Asm (1934) 

 states that Ceratopteris and Marsilea are not mycorrhizal, thus con- 

 firming Stahl, who had also found Pilidaria globulifera non-mycor- 

 rhizal. 



Of all the Pteridophytes, the Ophioglossaceae have been most 

 studied for symbionts. Janse, who worked at Buitenzorg, had found 

 branched hyphae and sporangioles in the third layer of cortex only, 

 in Ophioglossum pendulum; while a few years later Campbell (1907), 

 working in the same place, found the same form of endophyte in both 

 gametophyte and sporophyte, infection of the sporophyte occurring 

 chiefly from the gametophyte. O. moluccanum and O. simplex have 

 also been studied carefully and found to be characteristically mycor- 

 rhizal. Helminthostachys, at first reported to be without endophytes, 

 was studied later (Lang, 1902) and found tO' be essentially similar 

 in its symbiotic relationships to Ophioglossum. Fourteen species of 

 Botrychium have been examined for endophytes and proved to be 

 mycorrhizal: of these, twelve were studied by Grevilltus (1895) 

 who stated that in these species hyphal formation always occurred in 

 the roots. Both generations of Botrychium are mycorrhizal, infection 

 taking place through the rhizoids. 



All of the five genera of Marattiaceae have been studied and found 

 mycorrhizal. The tree-like Angiopteris of the Orient tropics is re- 



