Kelley — 4 — Mycotrophy 



and forcing the water on through the tissues. Mollberg in 1884 

 questioned whether the fungal endophyte brought any nutriment to 

 the orchid; while Eidam in 1879 attempted to culture the fungus by 

 allowing fungi to develop on orchid "roots" placed in damp air. 



Mycotrophy in Ferns and Fern Allies: — ^^A yellow matter similar 

 to that found in orchids was found in lycopods by van Tieghem in 

 1871. He described this substance, and it was further described by 

 Bruchmann in 1874, who found it free from starch. Bruchmann 

 noticed, too, that in older tissues the fats and nitrogenous substances 

 dwindled in amount while a quantity of chrome-yellow granules ap- 

 peared. Ten years later (cf. Treub, 1884) it had become established 

 that endophytes are generally distributed in lycopods and that their 

 presence is not harmful. Indeed, Treub regarded them as commensals. 

 In ferns, especially the Ophioglossaceae and Marattiaceae, fungal 

 infection had been reported, and also presence of yellow matter. 

 Since the infection was present in fern stems, these structures were 

 appropriately termed fungal-rhizomes or mycorrhizomes. The term 

 mycorrhizome was coined by Dangeard in 1891, in his study of 

 Tmesipteris. 



Mycothallism in Liverworts: — In various liverworts a foreign 

 substance was observed in the form of large brown cask-shaped 

 structures (Milde, 1851), the significance of which could not be 

 discerned. But Gottsche in 1843, as earlier stated, had observed 

 a system of branching tubes in Aneura; and these tubes were definitely 

 described as hyphae by Leitgeb in 1874. Since the thallus of the 

 liverwort harbours a fungal endophyte, it is known as mycothallus. 



Earliest Observations of Mycorrhizae: — The association of 

 fungi with roots of higher plants has long been known. In Theo- 

 iHRASTUs' Enquiry Into Plants (according to Hort's translation) 

 we read: "For as for the fungi which grow from the (oak) roots 

 or beside them, these occur also in other trees." Theophrastus (or 

 Tyrtamus, to use his proper name) may have been walking in a 

 woodland and observed sporophores of fungi which he seems to have 

 traced to tree roots. It is a long step from the third century B.C. to 

 A.D. 1829, but the next reference to mycorrhizae was made in the 

 latter year by Meyen. In a short paper he called attention to peculiar 

 structures which he found on beech roots, which he believed were 

 beginnings of parasitic plants. Perhaps they were mycorrhizae, 

 perhaps not. But attention was being directed to root structures and 

 little by little knowledge increased. In 1837 Link stated that most 



