311 
perish in turn, and the process is repeated each season, resulting in 
a large, deep wound. When two or three such wounds are present 
on different sides of the stem, its stability is much diminished, and 
it frequently breaks at the injured part. 
e 
Judging from the literature pertaining to plant diseases, galls 
answering to the description of crown-gall, are by no means 
uncommon in every country where fruit trees are grown. 
According to Toumey, crown-gall is most destructive to nursery 
stock, as the disease spreads rapidly along the rows, killing a large 
number of seedlings outright. The widespread dissemination of 
the disease in the United States is attributed to the wholesale 
distribution of infected stock from nurseries, also to negligence in 
the disposal of diseased material. Co) trees become. 
infected the galls may continue to be produced for many years, 
the tree living on, but making less growth and producing a smaller 
quantity of fruit, and of an inferior quality to that of a healthy 
tree. Under such circumstances it is false economy to allow such a 
tree to remain standing. : 
It is estimated that $1,000,000, possibly much more, is lost 
annually in the fruit-growing districts of the United States through 
this disease, . 
When trees are not badly diseased, Toumey found that by cutting 
away the galls, and covering the wounds with a paste composed of 
two parts sulphate of copper, one part sulphate of iron, and three 
parts of quick-lime, the further development of the galls was 
arrested. On the other hand, it is considered that in the end the 
most economical course is to remove and burn all trees that are at 
all badly infected, as such constitute centres of infection from which 
many years, should not be allowed to monopolise the space that 
could be more profitably occupied by a healthy tree. 
Quick-lime should be worked into the soil in orchards known a 
be infected. Finally, nursery stock should be critically examine 
d 
Following on Toumey’s investigations, Erwin F. Smith = 
. O. Townsend have devoted a considerable amount of time an 
growths, and furthermore that Bacterium oot fi onic tie 
the mischief, is a new species. seat to these a t 
Toumey’s myxogaster is a secondary agent. ‘fen 
certain, the galls investigated by the different authors mention 
by Smith an 
Infektionskr,” 20, p. 89 (1907). 
A 2 
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