CHAPTER VIII 

 CULTURE METHODS AND APPARATUS 



Introduction. The artificial cultivation of bacteria marks 

 the beginning of the science of bacteriology. Little was done 

 with the bacteria or known about them until it was possible 

 to cultivate them artificially. The methods of cultivation 

 were difficult and rather slowly developed. Since bacteria 

 occur always in nature in a mixed culture, practically no 

 progress was made until methods of isolation were devised. 

 The picking up of the single organism was so difficult a task 

 that it was first done by Barber within the last few years. A 

 considerable number of different people have taken part in 

 the development of our present methods, but it is really to 

 Robert Koch that chief credit is due,- and his plate culture 

 method of isolation really marks the beginning of accurate 

 work in this line. When a single organism is planted on a 

 solid culture medium, the resulting mass of growth is called 

 a colony and is evidently made up of the descendants of a 

 single cell. When a colony is obtained, we have a material 

 for making subcultures, microscopical examinations, animal 

 inoculations, etc. Cultures made from a single colony are 

 called pure cultures, and in studying any organism the first 

 requisite is to get a pure culture. When this is obtained, the 



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