256 BACTERIOLOGY OF THE EYE 



to the appearance described by the older Vienna school as pustular 

 conjunctivitis. Morax does not consider that these limbal eruptions 

 should be identified with the true phlyctenules ; he describes them as 

 vesicles, in contradistinction to the subepithelial nodules, which are 

 the true phlyctenules. Uhthoff, Schmidt-Rimpler, and Schleich and 

 Reuchlin have stated that the formation of such a limbal eruption is not 

 absolutely dependent upon so-called scrofula ; this appears likely from 

 the fact that the diagnostic tuberculin reaction often fails in patients 

 with a few phlyctenules. With regard to the cases of recurrent kerato- 

 conjunctivitis, with the characteristic appearance of vessels in the 

 cornea (especially pannus and keratitis f asciculosa) , the view that their 

 occurrence requires not only an external irritation, but also some 

 special state of the nidus, cannot be rejected. I have always obtained 

 a positive reaction with tuberculin in these cases. 



The observations quoted above that, as a matter of fact, the 

 ordinary forms of infection can produce such symptoms in scrofulous 

 persons, show that an infection from without may be the cause 

 of a phlyctenular eruption. It is, however, not yet proved 

 that the phlyctenules are caused by a local infection with these 

 organisms. 



The cases where phlyctenules occur in a conjunctivitis due to the 

 ordinary organisms are specially worth examining, to determine 

 whether the individual phlyctenules are caused by the local inocula- 

 tion with these organisms or not. A negative result of such an 

 examination, at any rate, would be strong evidence that the phlyc- 

 tenules could occur in an irritated conjunctiva without any localized 

 inoculation. 



On the evidence before us it is hardly probable that kerato-conjunc- 

 tivitis is a clinical etiological entity of specific nature. It is more 

 probable that it indicates the manner in which the conjunctiva, of 

 scrofulous persons especially, reacts to various forms of irritation. 



If we still consider, from theoretical grounds, that cases may be infec- 

 tions, which with our methods appear to be bacteriologically negative, 

 then we must suppose that in these cases we have to do with some 

 unknown organism; and this can naturally also be the case with 

 regard to the occurrence of the individual phlyctenules. The possi- 

 bility is not altogether excluded that we have to do with an endo- 

 genous irritation. We have circumscribed lesions occurring in the 

 clear cornea in herpes zoster and also in herpes febrilis, and we have 

 also undoubted cases of endogenous conjunctivitis in metastatic 

 gonorrhoea, and after experimental injections of pathogenic Hefa 



