§2 QUINCE CULTURE. 
and friends. The two trees had been ten years planted, 
and show what can be realized from the most favorable 
conditions of growth and marketing. From the prices 
reported in several other States, the successful cultivator 
of this fruit could not fail to make it profitable. 
CHAPTER XVII. 
DISEASES OF THE QUINCE. 
DISEASES in trees arise from a variety of causes, such 
as insect depredations, loss of vitality from bacteria, and 
fungi preying on the living tissue; or there may be organic 
disease reproduced from unhealthy stocks and seeds. 
One form of existence is destroyed to produce another. 
‘The elements of life by death and decay enter into new 
forms of life. Disease in one department of nature may 
provide for a want in another. 
The chief known causes of disease in quinces are 
bacteria and fungi. ‘They are both low forms of vege- 
table life, the first multiplying by the division of a single 
cell, the second producing several spores inacell. Of 
the various bacteria, each acts in a way peculiar to itself. 
Some produce disease, some act as ferments, others assist 
in the ripening of fruits, and still others aid in the re- 
generation of organic matter to form cell-structure. 
The fungi are cellular, flowerless plants, which receive 
their sustenance from the earth or the organized bodies 
on which they grow. They differ from cther plants, in 
general, in chemical composition, being chiefly nitrogen 
instead of carbon; and in their method of growth, ab- 
sorbing oxygen and giving out carbonic acid. All the 
higher forms of plant life may have one or more of these 
low forms to prey on it as a parasite by its absorbing 
