RESULTS OF BACTERIA GROWTH 121 



These facts, too, show the desirability of having the 

 walls of kitchens and pantries smooth and glazed, in order 

 that they may not furnish lodging places for air bacteria 

 and may be cleaned readily with a damp cloth. They also 

 show us that lace curtains and heavy hangings around 

 rooms will be lurking places for numerous organisms. 

 This may do no harm in ordinary parlors, rooms where 

 the bacteria are mostly harmless and where no food is 

 kept, but should never be allowed in kitchens, and should 

 be most emphatically forbidden in sick rooms where dis- 

 ease germs are likely to be floating about in the air. 



THE RESULTS OF BACTERIA GROWTH 



The bacteria with which we are concerned all require 

 complex foods. Some species can live upon simple min- 

 erals from the soil, but these are of no importance in the 

 household. All that are of interest for our purposes feed 

 upon substances quite similar, in general, to those upon 

 which animals subsist. Any materials containing sugars, 

 starches, proteids (albumen, lean meat, etc.), or other ani- 

 mal foods, furnish excellent nourishment for bacteria. 

 For this reason the bacteria are in a sense the rivals of 

 the animal kingdom. Both animals and bacteria feed upon 

 the same kind of food, and both are, therefore, constantly 

 seeking to obtain and use it for their own purposes. 



When we bear in mind the facts thus far outlined we 

 can easily understand why bacteria play such an important 

 part in the affairs of everyday life. They are too small to 

 see, but are capable of inconceivably rapid multiplication. 

 They are all about us in great numbers, in earth, air, and 



