404 W or maid. — ‘ Brown Rot ’ Diseases of Fruit Trees . 
P'ig. ii. As in Pig. io, but 5 days later ; the canker has nearly girdled the stem. 
Fig. 12. A canker, from an apple tree infected with M. cinerea f. mali , bearing pustules during 
the third year after infection ; photographed in January, 1919. (The same canker photographed in 
1917, one year after infection, is shown in the Jour. Bd. Agric., Aug., 1917, p. 504, Pig. r.) 
Fig. 13. Dead spur and canker from an apple tree (var. Warner’s King) photographed Mar. 22, 
1918 : result of inoculating a single flower of the inflorescence in May, 1916, with conidia from a pure 
culture of M. cinerea f. mali. The canker produced in 1916 is nearly covered by callus, but the spur 
still bears pustules of viable conidia. 
Fig. 14. Dead spur and canker of an apple tree (var. James Grieve), winter condition, the 
result of the natural infection of the fruit with M. fructigena during the previous summer : the fruit- 
stalks, from which the diseased apples had fallen, are seen at the apex of the spur. The fungus was 
isolated from barren pustules on the spur and from mycelium in the canker. (Compare Fig. 3, 
which shows the summer condition of the fungus on an apple spur.) 
Fig. 15. Above are two flowering spurs which had become infected by M. cinerea f. mali , 
resulting in a canker on the branch. The check to the upward flow of sap stimulated buds below 
the canker to grow out into weak vegetative shoots. 
Fig. 16. Section through an infected spur and canker of an apple tree. The lesion on the 
branch is being covered by callus, x 2. 
