THE CONJUNCTIVA I3I 



proportion to its length, does not stain by Gram, and is fre- 

 quently intracellular, the cells then containing large numbers of 

 bacilli, though it may be necessary to search over a considerable 

 area of film before an affected cell is seen. It is advisable to 

 search for the organisms in a thionin or Loffler's blue specimen, 

 as it will probably be more distinct than in the Gram specimen 

 counterstained with carbol fuchsin. 



If the two occurred in the same region, it would probably be 

 indistinguishable microscopically from the influenza bacillus ; 

 they differ, however, in cultural characters. 



It causes the common self-limited variety of acute or chronic 

 conjunctivitis. There is no danger that the cornea may become 

 infected ; the disease is very contagious. 



The bacillus of Movaxand A xenf eld (Pls^te IV., Fig. 3) causes the 

 dry conjunctivitis which occurs especially along the edges of the 

 eyelids and at the angles of the eye, and which does not tend to' 

 cure in the absence of appropriate treatment. The secretion is 

 usually very scanty, and not purulent ; it is best collected from 

 the caruncle, and it may be necessary to use a capillary pipette 

 for the purpose. 



It is readily recognized as a rather large, broad bacillus, with 

 the sides parallel and the angles slightly rounded, and two bacilli 

 are often seen with their ends approximated together. It is most 

 frequently extracellular, but some bacilli are frequently seen within 

 the cells. Gram's stain is not retained. It grows readily on blood- 

 serum, which is rapidly liquefied. 



Of the rarer causes of conjunctivitis, the staphylococcus, strepto- 

 coccus, and pneumobacillus may be mentioned. The latter may 

 be recognized by the presence of a capsule surrounding a bacillus 

 which greatly resembles an elongated pneumococcus, which does 

 not retain Gram (Plate III., Fig. 3). 



Diphtheria aifects the conjunctiva, and its clinical recognition is 

 not usually difficult But the bacteriological diagnosis (without 

 the use of animal inoculations) is complicated by the fact that 

 an organism — the xerosis bacillus — which closely resembles the 

 diphtheria bacillus may occur in the conjunctiva either in health 

 or in disease. It does not appear that the two can be differen- 

 tiated with certainty by morphological appearances, staining 

 reactions (the xerosis bacillus often shows polar granules), or 

 even by cultural tests. The xerosis bacillus is believed to be 

 a harmless saprophyte. 



