ANAEROBIC METHODS 231 



From what has been said, it may be inferred that the cul- 

 tivation of anaerobic bacteria is a simple matter attended 

 with but little difficulty. Such an opinion will, however, 

 be quickly abandoned when the beginner attempts this part 

 of his work for the first time, and particularly when his 

 efforts are directed toward the separation of these forms from 

 other organisms with which they are associated. The 

 presence of spore-forming, facultative anaerobes in mixed 

 cultures is always to be suspected, and it is this group that 

 renders the task so difficult. At best the work requires undi- 

 vided attention and no small degree of skill in bacteriological 

 technique. 



