378 W or maid. — ‘ Brown Rot ’ Diseases of Fruit Trees . 
The apples infected with M. fructigena became within eight days 
discoloured over more than half the surface ; in one case the whole surface 
was brown. At this stage a pale raised circular pustular zone, covered by 
the epidermis, had developed at approximately i cm. from the point of 
inoculation ; a few days afterwards yellow pulverulent fructifications of 
M. fructigena burst through the skin in that zone,, and later numerous 
pustules appeared on the rest of the surface. 
Of the apples infected with M. cinerea two had become discoloured 
over three-fourths of the surface, the other two over the whole surface, but 
no pus tides had developed. 
In both series the apples in which inoculation had failed to produce 
infection were still on the tree on July 20, as were also all the control 
apples. 
Strains used 
Experiment 5. 
Monilia cinerea forma mall 
Monilia fructigena , strain from an apple spur. 
This experiment was carried out on apples (var. James Grieve) growing 
in the College plantation. The apples were inoculated on July 24 by 
making in each a single puncture with a sterile needle, and inserting in the 
puncture a particle of a pustule obtained from a pure culture of the fungus 
growing on sterilized potato. Ten apples were inoculated with each of the 
two strains, and, to serve as controls, ten apples were punctured but not 
inoculated. 
M. cinerea 
f. mali. 
Result. 
July 26. 
Rot had commenced in all the 
apples, the brown areas round the 
punctures varying from 3 to 13 mm. 
in diameter. 
July 30. 
About half the surface of each was 
discoloured ; four of the apples bore 
no pustules whatever, four had a few 
scattered pustules, and on one only 
were they at all comparable in 
number to those occurring on the 
apples infected with M. fructigena ; 
the pustules were ashy grey in colour 
and the largest was about 0-5 mm. 
in diameter. 
M. fructigena. Rot had commenced in all, the About half the surface of each was 
affected area being 3-13 mm. in discoloured and all bore yellow 
diameter. (light buff) pustules to 2 mm. in 
diameter ; the pustules were almost 
localized to a definite circular zone 
at about 1 cm. from the point of 
inoculation. 
No rot appeared on any of the control apples. 
Strong winds, which occurred early in August, detached all the 
inoculated apples except one. The exception was one infected with 
M . fructigena. which had been in contact with the bark of the branch ; 
the development of numerous pustules served to attach the apple to the 
