Wormald. — ‘ Brown Rot ’ Diseases of Fruit Trees . 367 
the apothecia were developing from mummied fruit which had been lying 
on the ground for some time in an old peach orchard. Many bulletins on 
Brown Rot appeared during the succeeding ten years, dealing chiefly with 
the therapeutics of the disease, which was still generally attributed to 
Monilia frtictigena. Then a series of papers appeared, written by Jehle 
(1913), Matheny (1913), Cooley (1914), Conel (1914), Valleau (1915), Brooks 
and Fisher (1916), and Bartram (1916), in which the writers conclude that the 
Brown Rot organism occurring in America is identical with Monilia cinerea. 
Bon., of Europe. ‘ Peach Canker,’ attributed by Jehle to Sclerotinia cinerea 
(1913) or A. fructigena (1914), is found by McCubbin (1918), working in 
Ontario, to be due' mainly to Valsa leucostoma , though the initial lesions 
in many instances are caused by the ‘ Brown Rot fungus ’. 
The Brown Rot diseases are also common in Australia , 1 and in New 
Zealand, as shown by Mansfield (1916), Cockayne (1918), and Cunningham 
(1918). 
Articles recording experiments bearing on the physiological activities 
of fungi frequently give some attention to the Sclerotinias of fruit trees, 
e.g. Behrens (1898), Schellenberg (1908), Bruschi (1912), Cooley (1914), 
and Brooks and Cooley (1916). 
III. General Observations. 
In addition to observations already recorded in reference to a ‘ Blossom 
Wilt and Canker of Apple Trees’ ( 1917 ), and a ‘Wither Tip of Plum 
Trees’ ( 1918 ), examination of diseased fruit trees in various districts of 
Kent, and of specimens received from other sources, has yielded further 
interesting information relative to the occurrence and mode of parasitism of 
Monilia cinerea and M. fructigena, and the following notes supplement 
those records of observations in the open which have already been 
published. 
(a) The Occurrence of Monilia fructigena and M. cinerea on Prunus spp . 
It has been generally assumed that M. cinerea is wholly, or almost, 
restricted to the stone-fruit trees ( Prunus spp.), and M . fructigena to species 
of Pyrus. This assumption has arisen from the observations recorded by 
continental workers, and does not necessarily obtain in this country ; in 
fact, M. fructigena is often found on cherries and plums, while a form of 
M. cinerea is responsible for a serious Blossom Wilt of apple trees. The 
records of the occurrence of M. cinerea on stone-fruit trees on the Continent 
have been chiefly in reference to the disease on the ‘ Sauerkirsche ’. The 
acid cherry trees grown in England are also very susceptible to attack from 
M. cinerea , the blossom, fruit, and branches being killed ; in no instance 
have I foufid M . fructigena on the acid cherry. In Kent the sweet cherries 
1 Vide McAlpine’s ‘ Fungus Diseases of Stone Fruit in Australia’, p. 53. Melbourne, 1902.- 
