16 HOUSEHOLD BACTERIOLOGY. 



Names of All of these dust-plants have to be studied under 



Dust Plants 



the 'microscope and are therefore called micro-organ- 

 isms. Microbe a name given by Louis Pasteur 

 which from its derivation would include all, has 

 come gradually to be applied to one class, the bac- 

 teria. Still a third word, germ, which really means 

 the beginning, or that first living cell which produces 

 a more complex form, is becoming restricted to the 

 micro-organisms that cause disease, as the germ of 

 tuberculosis, the germ of typhoid fever, etc. All 

 these names may apply to micro- 

 scopic animal forms as well. Strict- 

 ly speaking, all dust-plants are germs, 

 all are microbes, all are micro-organ^ 

 isms. 



The "garden" will show two 

 kinds of plants and sometimes a 

 third, although this is not so com- 

 mon in house dust. We will now 

 see what these three kinds of plants 

 are > two of which we may expect 



tO filld in a11 h USeS at an . V timC ' 



Forma. (b> Baeiin The third, wild yeast, would verv 



or Rod-shaped 



Mil 8 ' or J sp i f ft n 'kely ke caught if we planted our 

 forms. d us t garden under the apple trees in 



summer time. 



BACTERIA 



Let us find out first what the plants are like which 

 make the smooth, glossy, shiny colonies, whether round 

 or radiate. These are the bacteria, and each colony 



