after it died, to have new shoots appear from the old roots 

 and grow to be good bearing trees. (Pear.) 



Blight always kills the parts of the plant affected. Al- 

 though the term blight is restricted in its true sense to this 

 particular disease of the leaves and stems with their fruit 

 which is often itself affected, due to a spreading of the dis- 

 ease to it from the stem, nevertheless, there are diseases of 

 the fruit itself that do not involve other parts of the tree, 

 which diseases are the result of a cause, the nature of which 

 is like the cause of true blight. When the fruit alone is 

 effected with a blight that does not spread to other parts of 

 the plant, we call this disease Mot as a rule, although the 

 term rot is also applied to diseases of the fruit, the cause of 

 which is entirely different from that of true blight. There 

 are cases, however, where true blight may begin in the fruit 

 or even blossom before the fruit is formed, and from it 

 spread to the stem and leaves. In this case Waite has 

 demonstrated that insects are the active agents in carrying 

 the disease from one place to another; and that they inocu- 

 late the flowers which may have produced minute fruit be- 

 fore the disease increased so as to kill it and spread to the 

 twig, or the disease may have increased so as to prevent the 

 least formation of fruit. 



THE NATURE AND CAUSE OF BLIGHT. 



The disease known as blight is caused by bacteria. Bac- 

 teria are plants that are so small that in some cases twenty- 

 five thousand (25,000) of them placed side by side would 

 extend but one inch. Most bacteria, however, are a little 

 larger than this, while many are smaller. They are as a 

 group the smallest of living things, but what they lack in 

 size they make up in numbers. Their power of multiplica- 

 tion is so great that in many cases, when every thiug is fa- 

 vorable as regards food and temperature, the result of the 



