280 



BACTEKIOLOGY OF THE EYE 



The Pneumococci in the sac as a rule are derived from the conjunctiva ; they 

 rarely come from the nose. The increase in virulence may be due to the fact that 

 in the sac they are at a higher temperature, one nearer that of the body than 

 obtains in the conjunctiva, and also because they are better nourished than in the 

 conjunctival fluid. Perhaps the lower acidity has an influence. Gifford has shown 

 that the Pneumococcus, although a facultative anaerobe, retains its virulence longer 

 when cultivated from the conjunctiva if kept free from acidity (by the method of 

 Buchner). When the growth of pyogenic Pneumococci is examined after the 



extirpation of the sac, we find them 

 rapidly disappearing from the con- 

 junctival secretions (Plaut and von 

 Zelewski), a further illustration of 

 the difference in the nutritive con- 

 ditions in the two places. 



In the truly acute purulent 

 ' pericystitis ' chain - forming 

 cocci are found, having all 

 the characteristics of the 

 Streptococcus pyogenes. They 

 are, however, not so common 

 in simple dacryocystitis, where 

 the Pneumococcus is the most 

 important. Acute phleg- 

 rnonous conditions with Pneu- 

 mococci and catarrhal condi- 

 tions with Streptococci do 

 occur, even in one and the 

 same individual (Gabrielides). 

 Friedlander's Pneumo- 

 bacillus, or the so - called 

 ozsena bacillus, is found in 

 a smaller proportion of cases, 

 sometimes as the only organ- 

 ism present, sometimes along 

 with other organisms (Sattler, 

 Terson and Gabrielides, Mazet, 



Cue"nod, Uhthoff and Axenfeld, Gourfein). There was at first an 

 opinion prevalent, and strongly held by Terson and Gabrielides, that 

 these bacilli were of great importance in the sac, especially in the 

 pathology of hypopyon-keratitis, because ozsena was so commonly 

 present also. Results have not confirmed this opinion ; they have 

 certainly been found in many cases of ozaena (Terson and Gabrielides ; 

 Mazet, Lodato), but, as a rule, the hypopyon-keratitis in these cases is 

 caused by the Pneumococcus. In comparison with the organism which 



FIG. 52. CANALICULTJS AT THE ENTRANCE 

 INTO THE SAC, IN A CASE OF CHRONIC 

 DACKYOCYSTITIS (STOCK). 



Lumen filled with Pneumococci (blue) ; at one 

 place commencing eruption into the sur- 

 rounding tissues (pericystitis phlegmonosa 

 incipiens). 



