Wormctld. — ‘ Brown Rot ’ Diseases of Fruit Trees. 375 
Experiment i. 
Strains used 
f. Monilia cinerea forma mail. 
[M. fructigena , strain from apple spur. 
Two apples (var. Bramley’s Seedling) were each inoculated on one side 
with a strain of the apple Blossom Wilt form of Monilia cinerea , and on the 
opposite side with a strain of M. fructigena obtained from an apple spur 
which had become infected through the fruit. The inoculations were made 
on September 14, 1917, with the following results : 
September 21. In both apples on the side inoculated with Monilia 
cinerea the rot had extended 2 -5-4- 5 cm. from the point of inoculation ; no 
pustules were present, but conidiophores had developed along the cut at 
the place where the inoculation was made ; the discoloration was a deep 
brown, with darker, more or less concentric zones ; many of the lenticels 
were marked with dark circles. 
On the side inoculated with M. fructigena the rot had extended 
3-3*5 cm. ; a few yellow pustules, to 2 mm. in diameter, were present, and 
conidiophores had also developed along the wound ; the discoloration of 
the surface was a bright brown, except in the immediate neighbourhood of 
the point of inoculation, where the colour was darker for about 1 cm. 
October 12. M. cinerea had extended through about two-thirds of 
each apple, the surface on that side being black in colour ; the skin was 
hardly shrunken and bore no pustules. M. fructigena had made less 
progress, about one-third of the surface being affected ; the skin was bright 
brown in colour, much shrunken, and bore numerous yellow pustules. 
October 25. There was no further change except that the shrinkage 
was more pronounced, particularly on the side infected with M. fructigena. 
These results were essentially the same as those obtained in 1916, 
when a strain of M '. fructigena obtained from a plum had been compared 
with the Blossom Wilt form of M. cinerea (see Figs. 4 and 5). 
Experiment 2. 
~ . . ( Monilia cinerea forma mali. 
Strains used! r 
\Moniha cinerea forma prum. 
Two apples were each inoculated on one side with the apple Blossom 
Wilt strain used in Experiment 1, and on the other side with a c Wither 
Tip ’ strain of M. cinerea from a plum tree. The inoculations were made 
on September 14, 1917. 
