SPECIAL FORMS OF CONJUNCTIVAL INFECTION 207 



probability of Streptococci, in cases which show the appearance of Fig. i2, to 

 await the results of a bouillon culture. 1 



Streptococcus pyogenes only 

 rarely plays a part in the other 

 clinical types of conjunctivitis, 

 and mistakes can hardly occur. 

 In the secretion from the lac- 

 rymal sac the Streptococcus 

 has a great tendency to chain- 

 formation ; so also in the in- 

 terior of the eye, and especially 

 in the vitreous, where even the 

 so-called Streptococcus brevis 

 tends to grow in long chains. 



Cultures must be used to 

 differentiate this organism from 

 the Staphylococcus, which is 

 equally rare in the cornea, when 

 dealing with those rare strepto- 

 coccal infections where the 

 dense corneal tissues are not so 

 favourable to the formation of 

 chains, and the method of ob- 

 taining the material and rubbing 

 it out on the slide loosens the 

 cohesion of any chains which 

 may occur. 



The differential diagnosis from the Pnenmococcns by means of a slide is easy 

 and certain, as in no pneumococcal infection do the typical lancet forms fail 

 (cf. Fig. 30, Plate II., Fig. II., and 

 Plate III., Fig. I.). Of course, in a 

 pneumococcal exudation single round 

 Diplococci are often seen. The draw- 

 ings, made exactly from Nature, show 

 this in man}' places. In such cases we 

 cannot decide from the microscopical 

 findings whether we have a mixed 

 infection of Streptococci and Pneumo- 

 cocci or not. It should be noted in 

 this connexion that such a mixed in- 

 fection in the eye is very rare. I have 

 only seen it here and there in pus from 

 a lacrynial sac (and then long chains 

 were present such as the Pneumococcus 

 never forms in secretions). On the 

 other hand, in the hundreds of cases 

 of pneumococcal infection of the cornea 



FIG. 42. SECRETION FROM STREPTOCOCCAL 



NECROSIS OF THE CONJUNCTIVA. 



Many Diplococci, a few chains. 



FIG. 43. STREPTOCOCCAL Pus (ORBITAL 

 CELLULITIS). 



(ulcus serpens), which in the course of 

 years we have proved by cultures, we 



1 The case published by Haglund as one of Meningococcus was a pure diplococcal one. 

 In the secretion were only Diplococci, some mtra-cellular ; in. the cultures at first Diplococci, 

 then long chains. All these forms stained veiy intensely with Gram. This is not a true 

 Meningococcus. The Frankel Meninyococcus also forms chains. Fig. 44, from a Frankel's 

 preparation, shows only Diplococci in the secretion ; they stain partly by Gram, and thus 

 are different from the Weichselbaum Meningococcus. 



