94 QUINCE CULTURE. 
being inoculated with a piece of the surface of one dis- 
-eased, the spores germinated, and the rotting slowly 
progressed to the twenty-second day, under a bell glass, 
when the decayed spot was an inch and a half in diam- 
eter, and showed fruiting points of the disease. 
So long as the wax-like covering of fruit remains per- 
fect, it is difficult for the spores of disease to affect it; 
but the sting of an insect, the abrasion of a chafing limb, 
or a bruise will make a way for the germs of disease to 
enter. Hence the importance of great care in handling 
the fruit. No other preventive is known for this disease. 
8. Bark Bounp or Hive Bounp.—This may arise 
from the depredations of scale insects weakening the 
vitality of the cells, or it may arise from an undue reduc- 
tion of the top in pruning or grafting, producing a dis- 
proportion between the leaves and the numerous cells 
under the bark, by which their expansive force is weak- 
‘ened too much to push out the bark; or injury to the 
roots may so far weaken the power of these cells that 
they become unequal to the task required of them. Pro- 
vision is made for the expansion of the bark by the forma- 
tion of cork-like cells, called suber cells, which expand so 
as to rupture the outer bark, and allow a proper enlarge- 
ment of the growing tree. very tree has its own suber 
cell, and so the rifts in the bark of each are according to 
its own peculiar character, no two appearing just alike. 
When, from any cause, the tree has become bark bound, 
a slit of the knife will help in doing what these cells 
failed to perform. The slit should be very carefully 
made, lest, instead of helping, it injure the tree by its 
severity. Be very sure the malady exists before the 
remedy is applied, or great harm may follow. 
