THE DECAY OF FRUIT 41 



decaying apples, pears, lemons, and bananas, the differ- 

 ence in the character of the decay is quite evident both 

 to the eye and to the smell. Bitter rot, black rot, and 

 brown rot are three types produced by three different 

 organisms. It is not within the scope of our study to 

 describe the different kinds of decay which appear in com- 

 mon fruit. The causes may be numerous, but in the 

 majority of the examples of decayed fruit the active agency, 



FIG. 22. Monilia, a common species of mold causing fruit decay. 



at the start at least, is the growth of molds. In later 

 stages of the decay bacteria may be concerned, but it is 

 always molds that begin the process. There are a num- 

 ber of species of molds intimately associated with the 

 decay of fruits. The common blue mold (Fig. 7) is one 

 of the most widely distributed, but there are several others 

 (Figs. 22, 23, 24). 



METHOD OF INFECTION AND DISTRIBUTION 



To understand the decay of fruit we must first bear in 

 mind that mold spores are constantly floating in the air, 

 and that they may also be carried easily upon the feet of 

 insects that chance to light upon a bit of spore-bearing 

 mold. By some such agency mold spores are quite sure 



