146 BACTERIOLOGY OF THE EYE 



phasized the oft-repeated possibility that flies, which are very 

 numerous there, may assist in the widespread infection. 



As is shown by the work of Morax, Weichselbaum, Muller, and 

 Hofmann, we must also emphasize that the chronic forms, with their 

 slight and readily overlooked inflammatory symptoms, can serve to 

 spread the affection for months. The subsidence and reappearance 

 of epidemics can thus be explained. 1 Meyerhof similarly speaks of 

 chronic infection with acute exacerbations. 



Regarding the pathological anatomy of such cases, Morax and Mayou 

 found widespread mucous degeneration of the epithelium and infiltra- 

 tion of the mucosa, at first with polynuclear cells especially, later 

 with lymphocytes and plasma cells. 



(Prophylaxis directed against the Koch-Weeks bacillus takes the 

 form of cleanliness, and careful avoidance of direct or indirect con- 

 tamination with the secretion. Severe cases should be isolated. 

 Schools should be closed when they contain many severe cases. In 

 all cases those affected should be excluded. 



The most valuable treatment consists in the use of 1 to 2 per cent, 

 argenti nitras solution. Zinc, which is so useful in other infections, 

 especially the diplobacillary, is not much use in these cases. 



Thorough treatment of cases tending to become chronic is im- 

 portant.) 



Pathogenieity. Disposition. 



Morax, Hofmann, Weichselbaum, and Muller carried out experi- 

 mental inoculations, and found that the Koch- Weeks bacillus had no 

 action on animals. Monkeys, dogs, rabbits, guinea-pigs, rats, mice, 

 fowls, pigeons, calves, and young pigs proved refractory to all kinds 

 of subcutaneous injections and conjunctival infections. Even after a 

 condition of severe irritation had been produced in the conjunctiva, 

 as was done by Morax with jequirity to supply a disposition, no 

 bacterial action on the conjunctiva could be produced. At the site 

 of infection no organisms could be found after twenty-four hours. 

 Kamen alone once obtained a transient inflammation after inoculating 

 a rabbit with some of the pus. 



The bacilli, at any rate, cannot grow in the bodies of animals. 

 Rymowitsch attributes to them a toxic power similar to that of 

 influenza bacilli, which in large doses have a toxic action. 



The human conjunctiva, on the contrary, is very susceptible to 



1 Note that the same occurs in the case of influenza. Baumler, Pfeiffer, "\Vassermann, 

 Clemens, Parsons, and others, have demonstrated this long persistence, and attribute fresh 

 outbreaks of the epidemic to it. 



