350 
Garden Work 
to think of curing a plant suffering from bacterial disease 
by spraying it with a fungicide. 
There is a wide field for research in connection with 
these plant diseases. There is no absolute proof that 
diseases in animals and men are not able to infect plants, 
and afterwards to infect animals and men again. It is 
absolutely certain that some disease germs (bacteria), 
such as Bacillus tetanus — the germs of lockjaw, &c. — are 
able to live in the soil, and directly infect animals and 
men from it. Serious research work in this direction 
should be undertaken at once. 
Potato Bacteriosis — This disease has been studied 
by Dr. E. F. Smith. Its first appearance is detected by 
the shrivelling up of the leaves, after which brown streaks 
are to be seen in the stem, showing the progress of 
the disease, which passes down into the tubers (or under- 
ground stems). Here a brown ring is first formed round 
the tuber, a short distance from the outside, and this 
gradually becomes broader until the whole inside of the 
tuber is a mass of powdery substance, which simply teems 
with the germs of the disease (bacteria). If nothing 
has been done to stop this disease before this time the 
skin breaks and the bacteria are liberated into the soil, 
there to lie dormant until the next opportunity presents 
itself for entering the tissue of other potatoes, and 
starting the disease again. The bacteria multiply at an 
enormous rate. They consist simply of one cell when 
full grown, and multiply by dividing into two by the 
formation of a cell wall through the middle of the cell. 
These two divide again, and so on. This, going on very 
rapidly, causes them to increase enormously, but when 
