CONJUNCTIVITIS 129 



etc.) ; or whether an irritated condition of neighbouring parts lids, 1 

 etc. may not be reacting on the conjunctiva. 

 The following possibilities may occur : 



1. The causal agent, even though the disease be due to micropara- 

 sitic contagion, may not be demonstrable by any of our methods. 

 This is till now the case in trachoma (conjunctivitis granulosa), as 

 well as in a certain number of follicular cases of conjunctivitis which 

 are definitely infectious. 



The possibility of some still unknown Bacteria being the cause, 

 occurs with greater or less likelihood in other conjunctival inflamma- 

 tions e.fj., in spring catarrh (?), some of the scrofulous forms, and 

 Parinaud's conjunctivitis. 



But in negative cases, and especially in those numerous sporadic 

 cases which are not contagious, or appear not to be, we must consider : 



2. The possibility whether, and to what extent, there may be an 

 endogenous irritation affecting the mucous membrane. 



At first glance this possibility seems very remote. Can a catarrh of 

 a mucous membrane be caused by some detrimental influence, which 

 is brought to it by the blood-stream ? 



In bilateral affections, what can localize an infective causa noccns 

 in the conjunctiva? Is not this mode of origin always very hypo- 

 thetical and extremely unlikely ; and should we not rather presume, 

 in these negative cases, that the cause, though entering from without, 

 is not to be detected by our present research methods ? 



Such considerations are very much to the point, and it would be 

 quite wrong were we simply to say, in the cases still indeterminate 

 bacteriologically, that they are endogenous, just as diseases were 

 attributed formerly to a ' chill.' 



On the other hand, we are obliged to admit, as many do, the possi- 

 bility of endogenous conjunctival inflammations, seeing that we 

 definitely know of several indubitable endogenous forms. 2 



The Danish surgeons Brandes, 3 Larsen, 4 and Bergh, 5 first drew 

 attention to the fact that an endogenous gonorrhoaal conjunctivitis 



1 Such a secondary conjunctivitis is recorded in a case of molluscuni coutagiosum of the 

 lids (Peters, Elchnig). 



- Endogenous infection of the conjunctiva in severe sepsis is very rare, and need not be 

 considered with regard to acute conjunctivitis (Wagenmann, A. f. 0., 1888, xxxiv. 251 ; 

 Axenfeld, ibid., 1894, xvi. 4). 



* ' De Ophthalmia Rheumatico - gonorrhoica et de Forma Arthropathise Gonorrhoica 

 Chronica' (Hauniae, Dissertation, 1850). In this article we find a very good clinical 

 description. 



4 'Ugeskrift for Leeger,' 1851, S. 292. 



3 'Bidrag tie Kundskaben om Gonorre,' Kjobenharn, 1860. 



(Herr Lundsgaard in Copenhagen has called my attention to the articles in footnotes 3 , 4 , 

 and ', which appear to have been forgotten.) 



9 



