METHODS OF EXAMINATION 223 



methylene-blue ; and (b) by Gram's method. The use of the 

 latter is of course of high importance as an aid in the recognition. 



(2) As most of the pyogenic organisms grow readily on the 

 gelatin media at ordinary temperatures, pure cultures can be 

 readily obtained by the ordinary plate methods. But in many 

 cases the separation can be affected much more rapidly by the 

 method of successive streaks on agar tubes, which are then 

 incubated at 37 C. When the presence of pneumococci is 

 suspected, this method ought always to be used, and it is also to 

 l>e preferred in the case of streptococci. Inoculation experiments 

 may be carried out as occasion arises. 



In cases of suspected blood infection the examination of the 

 blood is to be carried out by the methods already described 

 (p. 72). 



