382 BACTERIOLOGY. 



will be seen with the 1/12 oil immersion lens either 

 an enormous number of characteristic Loffler-ba( illi, 

 with a moderate number of cocci, or a pure culture of 

 cocci, mostly in pairs or short chains (see Streptococ- 

 cus). In a few cases there will be an approximately 

 even mixture of Loffler bacilli and cocci, and in others 

 a great excess of cocci. Beside these, there will be 

 occasionally met preparations in which, with the cocci, 

 there are mingled bacilli more or less resembling the 

 Loffler bacilli. These bacilli, which are usually of 

 the pseudodiphtheria type of bacilli (see Fig. 46), are 

 especially frequent in cultures from the nose. 



In not more than one case in twenty will there be 

 any serious difficulty in making the diagnosis, if the 

 serum in the tube was moist and had been properly 

 inoculated. In such a case another culture must be 

 made or the bacilli plated out and tested in pure 

 culture. 



Direct Microscopical Examination of the Exudate. 

 An immediate diagnosis without the use of cultures 

 is often possible from a microscopical examination of 

 the exudate. This is made by smearing a slide or 

 cover-^lass with a little of the exudate from the swab, 

 drying, heating, staining, and examining it microscop- 

 ically. This examination, however, is much more diffi- 

 cult, and the results are more uncertain than when the 

 covers are prepared from cultures. The bacilli from 

 the membrane are usually less typical in appearance 

 than those found in cultures, and they are mixed with 

 fibrin, pus, and epithelial cells. They may also be 

 very few in number in the parts reached by the swab, 

 or bacilli may be met with which closely resemble the 

 Loffier bacilli in appearance, but which differ greatly 



