98 FRUIT VULTUBB. 



DISEASES. 



Fire Blight is ;iu obscure disease which has 

 proved very destructive, especially in some 

 sections of the West, destroying v^hole or- 

 chards, without the hope of remedy. In New 

 England it has not proved so fatal ; and yet in 

 some years it is so destructive that it has 

 caused more discouragement than all other 

 evils combined. The prevailing opinion is that 

 it is caused by microbes, commencing at the 

 extremities of the tree, and working down- 

 wards with their poisonous influence, until the 

 tree is killed. Recent experiments have dem- 

 onstrated the fact that bacteria penetrate 

 either the blossoms or the succulent growth 

 of the branches. Certain it is that the disease 

 seems to extend from the top downwards, dur- 

 ing the season of growth, the leaves withering 

 and turning black on certain limbs, the bark 

 turning dark as the disease descends. It is 

 also certain that amputation below the affected 

 part will in most cases arrest the disease. But 

 heroic surgery is often necessar}^ to make sure 

 of being below the virus. No definite theories 

 can be given in regard to soil, climate, or treat- 

 ment to prevent this disease. It is supposed 

 that too rank or immature growth, in rich, 

 damp bottom lands, favors the disease. 



