84 QUINCE CULTURE. 
take in a dozen of them at once. Hence the ease with 
which the disease may be spread. 
Prof. J. C. Arthur, botanist of the New York Agricul- 
tural Station, who has given much time to the study of 
this disease, suggests that ‘‘The bacteria escape from 
the tissues in the slimy drops that ooze out from the 
diseased parts, especially in damp weather. They are 
washed off and freed from the viscid part by rains, and 
upon becoming dry are taken up by the winds. Being 
now suspended in the air,a damp day, dewy night, or 
light rain would bring them in contact with the delicate 
surface tissues of fresh cracks or wounds, in the most 
favorable way to introduce the contagion. This is quite 
in accordance with the fact that the disease usually starts 
at the ends of the branches, but also appears sometimes 
on the larger limbs, and even the trunks. It also ex- 
plains the fact that the rankest growers are most subject 
to attack, these exposing more tender surfaces, and, upon 
the disease obtaining a foothold, furnishing more succu- 
lent tissues.” Insects are almost sure to carry the disease 
wherever they go, after contact with these exudations. 
The theory that ascribes the blight to bacteria is so 
well proved that it is needless to notice the older theories 
which obtained before 1880, when Prof. T. J. Burrill, of 
Illinois, began experiments to demonstrate this. ‘‘ The 
bacteria connected with pear blight are all of one kind, 
and of only one kind: not the bacteria of putrefaction 
or of animal diseases, but a kind that have never been 
found anywhere except in blighted fruit trees. These 
have been named Micrococcus amylovorus. The former 
word, the generic name, means very minute bodies; the sec- 
ond, or specific name, means that they are lovers of starch. 
They are very minute vegetable organisms, and live on 
starch or similar substances. They multiply by dividing 
into two, like the figure 8; these divide again, this process 
of division and subdivision going on very rapidly.” 
