332 INFECTIVE DISEASES. 



culture outfit and its contents should be disinfected or destroyed. 

 To inoculate the tubes the patient, if it is possible, should be turned 

 to the light, the mouth well opened, the tongue depressed, and the 

 swab, without touching the teeth or the tongue, should be passed 

 straight to the tonsils or pharynx, and especially to the membranous 

 exudate. The swab is carefully and quickly withdrawn, and at 

 once very gently rubbed over the surface of the blood serum. The 

 culture outfit is then sent to the laboratory with full particulars, 

 and the tubes are placed in the incubator at 37 0., and can be 

 examined after twelve hours. If the throat has been disinfected 



IS 





S'SSl? .-.! 



V"W.-V*y \ ^ 



^ "Wi ^ 



x >\ -> *>- " 



\t -\ " flr-f 



M'^t 



^^^fc - 



FIG. 127. BACILLUS OF DIPHTHERIA ; FROM A CULTIVATION ox BLOOD 

 SERUM, x 1000 (FRANKEL and PFEIFFER). 



before examination, this must be taken into account, as the failure 

 to find bacilli would not then necessarily indicate a wrong diagnosis. 

 In all undoubted cases of diphtheria, growths will be obtained either 

 in the form of a pure-culture of the bacillus, or far more commonly 

 there will alsolbe colonies of various bacteria, especially Streptococcus 

 pyogenes. 



Bacillus of Diphtheria Rods, straight or slightly curved. 

 3 to '8 /* in breadth, and 1*5 to 6'5 ft in length. They occur 

 singly, in pairs^ sometimes in chains, and sometimes as short 

 leptothrix forms. In some cultures very irregular forms are 

 observed, the bacilli being swollen at one or both ends or thicker 

 in the middle portion, or the bacillus may contain oval or spherical 



