124 BACTERIOLOGY OF THE EYE 



this organism, though in other people by contact transference it certainly acts as 

 the cause of conjunctivitis. On the one hand, a whole series of positive contact 

 infections of the human subject can be quoted, and, on the other hand, are my own 

 numerous negative inoculations ; yet these two sets of results are not contradictory. 

 (In this peculiar infectious disease and also in pneumonia climatic disturbances 

 very probably have an influence ; the ' chill,' which at one time seemed to be dis- 

 appearing from the medical vocabulary as unmodern, appears to again obtain its 

 rights.) 



The predisposing factors in the case of the diphtheria bacillus are fully considered 

 by Sourdille and Uhthoff, and all the later investigators agree with them. Proved 

 inoculations of this organism on man are not available, but Morax and Elmassian 

 have obtained a typical membranous conjunctivitis in rabbits by continued instilla- 

 tions of diphtheria toxin. It cannot be denied that toxic action is of great import- 

 ance in the production of the clinical appearances in many cases of diphtheria, nor, 

 in view of these experiments, that of itself it can produce a diphtheria. These 

 experiments are important because, using the bacilli themselves, analogous processes 

 can only rarely be obtained in animals (Henke, Papers from the ' Path. Institut,' 

 Tubingen, ii., p. 321). A single dose of the bacteria does not cause sufficient develop- 

 ment of toxin. The finding of virulent diphtheria bacilli on the healthy or simple 

 catarrhal conjunctiva (Pichler, A. von Hippel, Pes, McKee, Vossius and Wagner, 

 Mathiew) does not contradict this, and the last-named authors themselves did not 

 consider such findings as negativing pathogenicity. 



In spite of the fact that inoculations on the human subject have not been made, 

 we must consider the Streptococci as certainly having the power of producing a 

 conjunctivitis in many persons, seeing that, just as in the throat, a necrotic process 

 immediately follows their presence on the mucous membrane, and also because of 

 the very serious results in such cases. The experimental inflammation produced 

 by Bardelli with pure streptococcal infiltrated tissue is denied by Coppez ; the 

 organisms themselves and their endotoxins appear essential. 



The enormous frequency of Staphylococci on the normal conjunctiva, as well as 

 in inflammatory conditions with which they have nothing to do, leaves the patho- 

 genic nature of the less virulent members of this group, at any rate, improved. 

 We cannot, however, exclude the possibility that, where they occur in large numbers, 

 are virulent, and circumstances are favourable to them, they may occasionally cause 

 a conjunctivitis, especially of the pseudo-membranous form. In this case, too, 

 caution is necessary, for when large numbers of virulent cocci have been inoculated 

 (Leber, Sattler, and others), no catarrh of any consequence was ever obtained. 



We still have only very little experience about B. coli. There have been no 

 definite inoculations, but its occasional action as a cause of catarrh is made probable 

 by the cases recorded by Taylor, Axenfeld, Bietti, Groenouw, and Cramer, and also 

 by analogies from other mucous membranes. 



There is no definite proof of the power of the influenza bacillus to produce con- 

 junctivitis ; according to Giarre and Picchi, and Rymowicz, it occurs on the normal 

 conjunctiva. Inoculations on the human conjunctiva had no result (Luerssen, 

 Axenfeld). Seeing, however, that it occurs in large numbers, and without any other 

 organism, in the secretions from many conjunctival inflammations, the term 

 ' influenza bacillus conjunctivitis' is justifiable, especially as it very probably can 

 cause an inflammatory reaction upon other mucous membranes, particularly in the 

 air passages. 



The same is the case with the Pneumobacilli. We infer that they can produce 

 a catarrh from their severe pathogenic action in other tissues, in the lungs, and in 

 the accessory nasal cavities. 



Similarly it is very likely, from the most recent work of Michalski and Gourfein, 



