376 APPLICATION OF METHODS OF BACTERIOLOGY 



methods. Micrococcus catarrhalis, so often seen within the 

 bodies of pus cells in the nasal discharges of acute catarrh 

 also suggests the organism under consideration, but is -easily 

 differentiated by its growth on the ordinary culture media. 



Summary of Distinguishing Peculiarities. Since gonorrheal 

 discharges may be contaminated with pyogenic cocci other 

 than those causing the specific inflammation, it is important 

 in efforts to identify the gonococcus that the differential 

 tests be borne in mind and put into practice. The gonococcus 

 is differentiated from the commoner pyogenic organisms 

 by the following peculiarities. 



First, it is practically always seen in the form of diplococci, 

 the pair of individual cells having the appearance of two 

 hemispheres, with the diameters opposed, and separated 

 from one another by a narrow, colorless slit. (Is this the 

 case with micrococcus aureus or streptococcus pyogenes?) 



Second, in gonorrheal pus it is nearly always within the 

 protoplasmic bodies of pus-cells. (How does this compare 

 with the conditions found in ordinary pus?) 



Third, it stains readily with the ordinary staining reagents, 

 but loses its color when treated by the method of Gram. (Treat 

 a cover-slip from ordinary pus by this method and note 

 the result.) 



Fourth, it does not develop upon any of the ordinary 

 media used in the laboratory; while the common pus- 

 organisms, with perhaps the exception of the streptococci, 

 are vigorous growers and are not markedly fastidious as to 

 their nutritive medium. 



Fifth, when obtained in pure culture by either of the 

 special procedures noted above, its cultivation may be 

 continued upon the same medium; but growth will usually 

 not be observed if it is transplanted to ordinary nutrient 



