3235 
PREVENTIVE MEASURES. 
The disease, which spreads rapidly, was checked by spraying 
with a solution of potassium sulphide. 
Diseased usc UB should be removed, as the mycelium is 
probably nial in the tissues, and would consequently give 
origin to De ik thé following season. 
Quicklime should be placed on the soil under diseased plants 
for the purpose of TENAS the sporules produced from the 
fallen masses of gum 
SUMMARY. 
Gummosis of Prunus japonica, Thunb., is caused by a species 
Cladosporium, morphologically indistinguishable from Clados- 
porium epiphyllum. 
The masses of extruded gum are permeated with the hyphe of 
the Cladosporium, which bear large, thick-walled, dark brown 
cells, or masses of cells resembling micro-sclerotia at their Pe 
situated just within s qo puer of the mass of gum, and 
imparting to it a black c 
These a. mee and micro- sclerotia, when caused to germinate 
in the abse of air, give origin to myriads of very minute 
sporules, Vieh reproduce boue n by gemmation ; ; under 
these conditions hyphe are not formed. 
Grown in a nutrient eae in the presence of 
form of reproduction once known as Denatióm pulita M 
produced. 
Inoculation with the Dematium sporules produces the disease. 
No results were Anes from infections with the sporules of the 
anaerobic con 
Bacteria were period. enyen from the masses of gum during 
every phase of developmen 
DESCRIPTION OF THE FIGURES. 
Fig. 1. Portion of a branch of Prunus Japonica, Thunb., 
bearing two masses of gum ; nat, size. 
„ 2. Cladosporium-form of fruit; x 400. 
D ow pp of a a portion of the periphery of a black gum- 
ass, showing the hyph:e of the Cladosporium; x 80. 
a + Dark coloured tips of hyphe from the periphery 
of a gum-mass, bearing large, thick-walled, brown 
00. 
cells; x 
» 9. Large thick-walled, brown cells RE in a nutrient 
solut ion in the absence of air, and producing yeast- 
like cells, which reproduce Verdun i by gemmation ; 
x LJ 
J dA 
Stray cells which are emitting a germ-tube, seen in the 
terial described in 5. 
