STATE POMOLOGICAL SOCIETY. 



tion are floating free, and fasten upon any life, vegetable or animal, 

 where the conditions are favorable for its reception and growth. 

 A warm, humid, stagnant atmosphere is favorable to its propoga- 

 tion and growth, and a cool, pure, moving air the reverse, hence 

 follows the deduction. Some parasitic plants or diseases even 

 fasten themselves upon the skin of the apple, and under favorable 

 circumstances enlarge, spread over the surface, and, piercing the 

 flesh with minute rootlets, the whole soon becomes a decaying 

 mass of vegetable matter, upon which a dozen varieties of sporadic 

 plants are feasting. 



As temperature at the freezing point puts an end to all vege- 

 table growth, so an approximation not suflScient to injure the 

 apple will surely conspire to prevent the spread of vegetable dis- 

 ease or the growth of microscopic plants. The spores will fail to 

 attach and germinate, or may be killed outright by the low tem- 

 perature. 



But this question of plant diseases opens up an inexhaustible 

 subject, of which smut in grain, black-knot on trees, and the 

 potato disease are prominent examples, 



I only proposed to present the experience and theory of a suc- 

 cessful orchardist for your consideration. 



