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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 sporangiophores 
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 
