140 DIPHTHERIA AND PSEUDOD1PHTHERIA. 



and certain to rub all sides of the swab upon the serum. 

 After which the swab is returned to its tube, both tubes 

 plugged, and the whole outfit with the blank form filled in is 

 returned to the laboratory. On receiving the tube at the 

 laboratory it is incubated at a temperature of 37 C. for 

 twelve hours, at the end of which time it is ready for exami- 

 nation. If the case is one of diphtheria, the typical diph- 

 theria growth is found on the surface of the culture. This 

 consists of grayish or yellowish-white glistening spots, and a 

 cover-glass preparation made of these shows in typical cases 

 the Klebs-Loeffler bacillus, as short, thick rods, with rounded 

 edges, irregular in shape, showing a decided staining in some 

 parts of their body, deficient in color in other parts, and 

 characterized chiefly by the variety of form of the different 

 bacteria forming the culture. 



In exceptional cases it is possible to find colonies as early 

 as five or six hours after incubation. 



Indeed, for cases outside of the city limits, in the munic- 

 ipal laboratory in New Orleans, it has been possible to make 

 examinations of the swabs themselves by making cover-glass 

 preparations from the same even two or three days after they 

 were prepared, and in a great majority of the cases come to 

 a positive or negative conclusion, verified later clinically and 

 also bacteriologically, by cultures made from these same 

 swabs. 



It is essential for these examinations that the cultures from 

 the throats of suspected cases be made before antiseptics have 

 been applied to the throat, or, if that is not possible, the cult- 

 ures should be made at an interval of at least two or three 

 hours after such applications, as otherwise the antiseptics 

 may have acted on the bacilli on the surface of the membrane 

 and destroyed them or greatly inhibited their growth. 



PSEUDODIPHTHERIA. 

 Bacillus Pseudodiphtherise. 



Another source of error in the application of this method 

 comes from the pseudodiphtheria bacilli which are found in 



