286 A MANUAL OF BACTERIOLOGY 



or cocci or streptococci, and in a tropical abscess of the liver the 

 Entamceba histolytica. In buboes, cocci and streptococci, Ducrey's 

 bacillus and the plague bacillus may occur. In the eye certain 

 special organisms may be met with. Suppurating glands are 

 frequently due to the tubercle bacillus. In all cases the pus or 

 discharge should be collected with aseptic precautions in sterile 

 capillary pipettes or in sterile test-tubes at the time of operation. 

 The discharge from opened abscesses and from wounds is liable 

 to become contaminated and the original infection to be masked. 

 In septic wounds the infection may be a mixed one. 



In all cases the examination should be commenced as early as 

 possible. 



(1) Make several smears from the pus or discharge. 



(2) Stain one or two of these with Loffler's blue and one or two 

 by Gram's method. Mount and examine microscopically. 



(a) If Gram-positive staphylococci only are detected, the pre- 

 sence of the ordinary pyogenic cocci may be suspected. Proceed 

 as in 3 and 4. 



(b) If encapsuled Gram-positive diplococci are detected, suspect 

 the presence of the Diplococcus pneumonice, and proceed as in 3, 

 4, and 5. 



(c) If diplococci and tetracocci are present, note whether they 

 are in groups within the pus-cells ; if so, and if Gram -negative, 

 suspect the presence of either the gonococcus or Diplococcus 

 intracellularis meningitidis (see pp. 297 and 301). 



(d) If free Gram-positive tetracocci are detected, suspect the 

 presence of the Micrococcus tetragenus, and proceed as in 3 and 

 4 (rare). 



Staphylococci not infrequently appear in pairs and fours. 



(e) If streptococci are present, proceed as in 3, 4, and 5. 



(/) If bacilli are present, they may be the colon bacillus, the 

 Bacillus perfringens, the bacillus of malignant oadema, the bacillus 

 of Hibler, the tetanus bacillus, the typhoid bacillus, the Bacillus 

 pyocyaneus, or putrefactive bacilli of the Proteus group (which 

 see). The result of Gram-staining and the clinical history of the 

 case will be some guide. 



a. The colon bacillus, especially frequent in suppurative peri- 

 tonitis and in diseases of the urinary organs (see p. 464). 



/3. The Bacillus perfringens, the bacillus of malignant oedema 

 and the bacillus of Hibler are met with in foul wounds, especially 



