270 BACTERIOLOGY OF THE EYE 



emphasis on disposition, carried beyond any justification by the facts 

 of the case, is not in the interest of the truth, and tends to minimize 

 the importance of the specific infectiousness of the disease, and its 

 definite introduction in the individual case. 



Acquired immunity cannot be demonstrated, reinfections are not 

 uncommon, and a trachoma which has long been in a state of quiet- 

 ness can break out again. 



No life-period is proof against trachoma in any trachomatous 

 district. The particular age at which infection most commonly takes 

 place naturally depends on the local conditions, and will vary in 

 different localities. The view is gaining ground that in many tracho- 

 matous countries the disease is acquired in early childhood. This is 

 stated to be the case in Amsterdam (Straub), for the greater part of 

 Russia (Ewetsky and others), and particularly for Egypt, where large 

 series of experiments by L. Miiller and Morax have shown that in 

 children of the first year trachoma is already widespread, and, as in 

 adults, is often combined with other infections. The previous asser- 

 tion that children have a low susceptibility is not correct. 



It is doubtful whether any disease corresponding to trachoma affects 

 any of the other mucous membranes. The lacrymal sac alone appears 

 to be affected with true trachoma. The occurrence of single follicles 

 is not infrequent in simple dacryocystitis, but when they occur in the 

 enormous numbers which Kuhnt, Raehlmann, Werncke, Ischreyt, 

 Cirincione, and Basso found, they can be considered as a sign of 

 trachoma. This is just as valid a diagnosis as is made in the case of 

 the conjunctiva, as there, too, non-trachomatous follicles are fre- 

 quently enough seen in other forms of irritation. It is very strange 

 that the conjunctiva of the lacrymal sac is only affected in a proportion 

 of the cases, although in them all the infectious secretion comes in 

 contact with it. A case reported by Stock favours the spread of 

 trachoma in the subepithelial adenoid tissue of the tear passages. 

 This case is figured on p. 280 to show the enormous masses of the 

 Pncumococci which lie in the lumen of the canal. The specimen was 

 a fresh post-mortem one from a case of severe trachoma with a diffuse 

 infiltration, which had broken through the epithelium at one point. 

 Besides this, there was a fresh dacryocystitis with a few follicles. In 

 the secretions of dacryocystitis in trachomatous cases Pneumococci are 

 often seen. In spite of this, an ulcus serpens in such cases is very 

 rare, although disturbances of the epithelium are very common. 

 Uhthoff and Axenfeld consider that this is due to the frequent vascu- 

 larization of the cornea being unfavourable to the development of an 



