34 8 
Garden Work 
which have had such good results that there is now 
little fear of serious harm from attacks of this disease. 
The mycelium of this disease runs through the tissue 
of the leaves, sending out clusters of spores here and there 
on the surface. The summer spores are known as uredo- 
spores, and are produced in large numbers, germinating 
quickly, and soon covering the leaves with the disease 
if not checked. 
Later in the season, when the leaves are dying off, 
the teleutospores, which are able to exist through the 
winter, are formed. Should these come into contact with 
Chrysanthemums in thq spring, they germinate at once, 
and produce the disease. The leaves of all diseased 
plants should be carefully collected and burned, to prevent 
the teleutospores from again causing the disease in spring. 
If the disease is suspected, the plants should be sprayed 
at intervals with potassium sulphide, and any which show 
the disease should be taken from among the rest, and 
either treated separately or burned. Where the plants 
are grown inside, in the shelter of a glasshouse, the uredo- 
spores may be produced all the year round, but special 
spraying should be done, where the disease is suspected 
in these plants, to keep it in check. 
BACTERIAL DISEASES 
Bacterial diseases in plants are becoming known, and 
are much more difficult to deal with than the ordinary 
plant diseases, which to a certain extent live on the surface 
of the plants, or at least produce their spores on the surface, 
and can therefore be treated with fungicides and destroyed. 
