8o THE POPULAR SCIENCE MONTHLY. 



rapid decay, due to the development upon them of the Penicil- 

 lium, while all other portions of the fruit were in a normal con- 

 dition. 



There are many diseases due to those exceedingly minute 

 germs so widely talked of nowadays namely, the bacteria. They 

 attack animals and induce fevers of many sorts, and man sinks 

 before them with the dreaded cholera, consumption, etc. Plants 

 have their enemies among these micro-organisms, and apples do 

 not enjoy an immunity from them. The succulent substance of a 

 ripe apple is a favorite food for the bacteria, the only check upon 

 their abundant entrance being the tough skin. But there are too 

 many weak places, and it is presumable that these germs when 

 falling upon them are capable of beginning their course of rapid 

 multiplication which, when unchecked, reduces the fruit to rot- 

 tenness. In Fig. 4 is seen an apple under the apparently un- 

 broken skin of which in several places were decaying spots with 

 no signs of any other mischief-makers than the swarming mil- 



Fio. 4. APPLE BLOTCH. 



lions of the micro-organisms. As soon as the skin becomes 

 broken in any such places, the coarser decay germs enter and 

 quickly the fruit is overrun with a motley vegetation of various 

 molds. 



If we look further among the decaying fruits, it will not be 

 long usually before an apple is found that does not agree with 

 any of the descriptions given above. Perhaps it is healthy in all 

 parts save one, and that has no scab present. The blue mold is 



