252 DIAGNOSIS OF INFECTIONS OF THE OCULAR REGION. 



The B. xerosis is possibly a harmless organism and must not be 

 accepted as explaining an infection unless other factors have been 

 eliminated. 



Leprosy and tubercle bacilli may be found in corneal ulcerations. 

 The true diphtheria bacillus, which the xerosis so much resembles, 

 may cause a pseudomembranous inflammation. 



The gonococcus and the Koch-Weeks bacillus are usually re- 

 sponsible for the very acute cases of conjunctivitis. Both these 

 organisms are characteristically intracellular and are Gram negative. 



The diplobacillus of Morax and Axenfeld is more common in 

 chronic, rather dry affections of the conjunctiva. 



In cases of ozena with involvement of the nasal ducts Fried- 

 lander's bacillus may be found. 



Certain fungi of the genus Microsporum have been thought to be 

 the cause of trachoma, as have also certain bacillary forms. One 

 should be very conservative about reporting fungi in smears or cultures 

 of external surfaces. 



The larval stage of Taenia solium (Cysticercus cellulosae) has a 

 predilection for eye as well as brain. It is usually situated beneath 

 the retina. 



The adult Filaria loa tends at times to appear under the conjunc- 

 tiva or in the subcutaneous tissue of the eye-lids. 



Fly larvae have been reported from the conjunctival sacs in the 

 helpless sick 



