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than the plus strain. The sectoring and the colony differences which 

 he pictures are much like those shown for Helminthosporium in this paper. 

 He also adduces evidence to show that these plus and minus strains occur 

 in nature and have been isolated by independent workers. He attempted 

 in four ways to induce saltation artificially but met with no success. 

 Crabill (35) has reported, in abstract, "a somewhat similar mutation 

 in a fungus belonging apparently to the genus Phyllosticta." Blakeslee 

 (21) reports: ". . .in 1912-13 I found numerous variants of various de- 

 grees of distinctness in the offspring of a single plant (Mucor) obtained 

 by sowing non-sexual spores." Writing of Mucor genevensis he says (20): 

 "In all, somewhat over 38,000 colonies from individual sporahgiophores 

 have been inspected and a relatively large number of variants of different 

 degrees of distinctions have been obtained .... the mutants 

 tend eventually to revert to the normal type. Two, however, have seemed 

 more stable." He concludes: "They add to the evidence, already obtained 

 from other groups, that mutations are not restricted to processes involved 

 in sexual reproduction." 



Brierley (27, 28) reported an albino Botrytis cinerea which was a form 

 with pale sclerotia though the parent form always had black sclerotia. 

 This albino was observed to arise from a colony derived from a single conid- 

 ium and from a race that had been under culture for considerable time, 

 always producing black sclerotia. The purity of his culture seems to have 

 been carefully guarded, and this case, though standing alone, would furnish 

 positive evidence of the sudden occurrence of a hereditary difference in 

 this fungus. 



Dastur (40) in 1920 described saltations in Gloeosporium piperatum 

 consisting in the absence or presence of perithecia, acervuli, or setae, and 

 in the development of aerial mycelium. He says: "Thus all of a sudden 

 the original sterile culture broke up into two different strains, one producing 

 only perithecia on sterilized chilli stems and the other forming acervuli 

 with and without setae." Some of these strains were not constant in 

 character, but others persisted through many transfers. He states that 

 great or sudden variations have never been observed from conidial 

 strains, but that "in cultures made from perithecia of the strain 

 of Gloeosporium piperatum incredibly large and often very sudden variations 

 have been obtained." Burger (32) in 1921 reported mutation of several 

 types in Colletotrichum, involving permanent changes in many characters. 

 He found these occurring in cultures derived from single spores and showed 

 that they were permanent through the spores. Jennings (70), who worked 



