DISEASES OF PLANTS 



231 



by scratching the skin with a pin. Now touch the sur- 

 face of the water or the moldy spot on the fruit with your 

 finger, so as to get some of the spores on it, and rub it all 

 over the surface, especially over the scratches. Place 

 the fruit in a tumbler or glass jar, with a little water 

 at the bottom. Do not allow the fruit to touch the 

 water. Cover the jar or tumbler, so as to keep the air 

 moist inside. Let it stand for two or three weeks. 

 Does the mold always start where the skin is broken? 



FIG. 132. The blue mold has not spread from the moldy lemon to the 

 others in the box, because they have been carefully handled and their 

 skins are not broken. 



It is perfectly clear from this experiment that the growth 

 of mold can be prevented if care is taken not to break 



