Kelley — 40 — Mycotrophy 



etc. Other workers continued the reports, and, in 1935, Rayner re- 

 marked on "the remarkably widespread geographical distribution of 

 this 'Phycomycete type' of mycorrhizal association, its prevalence in 

 plant species of the most diverse affinities (and) its recorded appear- 

 ance in certain crop plants." Biraghi (1936) confirmed Peyronel 

 on the frequence of endophytic infection of roots of cereals, finding 

 Asterocystis radicis in a majority of cases. Ruggieri (1937) reported 

 endotrophic mycorrhizae common on fruit trees, a Phycomycete being 

 constant in root cortex of almond. Berkeley (1936) found a phy- 

 comycetous mycorrhizal fungus on raspberry in Canada; Richards 

 & McKay (1936), on strawberry in Utah; and Reed & Fremont 

 (1935), on Citrus. 



In 1939, Butler published a paper devoted to a study of "the 

 distribution and morphological characters of the vesicular-arbuscular 

 or Phycomycetoid endophytes which commonly occur in cultivated 

 and probably other soils forming mycorrhizal associations in the 

 roots of many flowering plants and cryptogams, including prothalli 

 of liverworts and of some ferns. The regularity of their occurrence in 

 some annual field crops is believed to be merely the result of the 

 greater opportunity to persist indefinitely, by passing from the older 

 to later developed roots, offered to the organism in perennial plants." 

 Believing with Peyronel that these fungi belong to the Endogyn- 

 aceae, Butler cites Dangeard's (1898) name of Rhizophagus for 

 their genus, and describes the species as R. populinus, R. theae and 

 R. marratiaceum. Sabet (1939) promptly placed on record the 

 presence of Rhizophagus sp. as the mycorrhizal fungus of cotton in 

 the Sudan. 



The first reputed synthesis of a Phycomycete mycorrhiza is said 

 to have been that of the unnamed endophyte of Arum with roots 

 of A. italicum (Magrou, 1936). 



Ascomycetous Mycorrhizal Fungi: — Various Ascomycetes 

 have been cited in connection with mycorrhizae, as Aspergillus and 

 PenicilUmn (Ternetz, 1907) ; Terfesia (Pirotta, 1900) ; MoUisia 

 (Nemec, 1899) ; and Humaria (Nicolas, 1929) ; but Elaphomyces 

 and Tuber are the most frequently reported of the group. Very 

 early, Boudier (1876) had noted presence of Elaphomyces on low 

 ground with Molinia, a grass ; or on higher grounds where Leuco- 

 bryuni moss was growing. Still earlier (1837), Berkeley had 

 cited the association of E. miiricatus with beech roots in mountainous 

 woods. TuLASNE (1841) remarked that E. granulatns is confined 

 to roots of one sort of tree (not named) and "flourishes when tree 

 is active." This same species Boudier had found on birch, oak and 



