BACTERIA OR GERMS 



But when we think of how man utilizes the work of plants 

 and animals, then the whole scheme becomes intelligible and 

 complete ; it is like a well-rounded story with a worthy and 

 adequate end. 



Moreover, what man has done so far is only an instalment 

 of what he will probably succeed in doing. All who have 

 brought up caterpillars or bees know that their greatest 

 difficulty arises from certain minute insects or fungus 

 enemies. We already know enough about these latter to 

 fight them with some chance of success, but there are 

 hundreds of other spores and germs floating in the atmo- 

 sphere, and coming to rest on animals, on clothing, or on the 

 leaves or petals of plants. These germs are now just as wild 

 as, and infinitely more dangerous than the furious aurochs, 

 the disdainful wild asses, or the ferocious wolves that our 

 forefathers succeeded in domesticating. 



Those bacteria, or germs, for instance, which are only 

 one-thousandth of a millimetre long, are only visible by the 

 help of a microscope. A row of three hundred thousand of 

 them would be required to make an inch in length ! Yet 

 one of these germs can be mature and divide into two new 

 germs in twenty minutes. In forty minutes there would be 

 four, in an hour eight, and so on. The number after twenty- 

 four hours is almost incredible. 



These little germs stick to our clothes, fingers, lips, 

 money, newspapers, and anything that is often handled. 

 They hover in the air we breathe, permeate the food we 

 eat, and inhabit water, and especially milk, in enormous 

 numbers. Some of them are deadly. One might easily 

 decimate a whole population, as indeed happened in the 

 South Sea Islands when smallpox was introduced. Others 

 are harmless and even necessary. 



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