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stomata, each thread being much branched at its tip, and each 
branch bearii ., conidium or reproductive body. 
These conidia are carried by wind or washed by rain from one 
leaf to another, where they germinate, and soon form a new 
centre of disease, from which conidia are liberated in rapid 
succession and in great numbers. In addition to the ±uv(:wv 
mould other bodies called oospores are formed on the mvrelium 
of tlie fungus present in the tissues of the leaf. These bodies are 
carried to the ground by the decaying leaves, where thev remain 
unchanged until the following season, when thev germinate, and 
if beet or mangold be present the plants are infected. 
Preventive measures.— Avoid sowing beet or mangold on ground 
that has produced a diseased crop of the same kind the previous 
season ; in fact it is not good policy under any conditions to 
attempt two root crops on the same land in e 
It has been suggested that when plants have been attacked by the 
fungus and have afterwards recovered, the mycelium hybernates in 
the neck of the root, and appears the following season, producing 
a crop of conidia ; it is therefore important not to plant roots for 
the purpose of producing seed that were grown in an infected 
If the disease appears among young plants, spraying with dilute 
Bordeaux mixture will arrest the spread of the fungus. 
Violet Root Rot. 
(Bhhoctonia violacea, Tul.) 
This very destructive disease is recognised by the presence of a 
more or less dense violet or brownish-coloured mould on the 
roots. The life history of this fungus has not been followed; 
several species have been proposed ; but as suggested by Tulasne, a 
French mycologist, probably all are forms of one species. When 
young plants are attacked they usually die gradually, whereas 
when the root is fleshy death is somewhat sudden ; large holes 
are formed in the flesh, the surface being covered with the brown 
mycelium of the fungus. Numerous small dark-coloured sclerotia 
or compact masses of mycelium are also usually formed in the 
decaying tissnes of the host; these are liberated in the soil, and 
enable the fungus to continue its existence from year to year. 
The disease occurs in patches in the field, which continue to 
increase in size. A single beet is first attacked from which the 
mycelium spreads in the soil, attacking in turn neighbouring 
plants. Owing to the great number of different kinds of plants 
on which the fungus can live, it is very difficult to eradicate 
when it has once gained a foothold. Carrots, turnips, potatoes, 
lucern and saffron are all attacked. It has been stated that saffron 
and potatoes have been attacked after an interval of twenty years' 
rest from such crops on land that had previously produced a 
diseased crop. Spores or special reprodm tive bodies are unknown, 
the fungus reproducing itself from year to year by means of its 
mycelium and sclerotia. It is very probable that the fungus 
derives food from various weeds as well as from cultivated plants. 
