ACNE 



227 



in the more subacute cases of conjunctivitis. Eyre found it in 



2 '5 per cent, of all cases of conjunctivitis. Its cultural characters 



are given below. The xerosis bacillus, which is a small diph- 



theroid organism (Fig. 123), has been found in xerosis of the 



conjunctiva, in follicular conjunctivitis, and in other conditions ; 



it appears to occur sometimes also in the normal conjunctiva. 



It is doubtful whether it has any pathogenic action of importance. 



Acute conjunctivitis is also produced by the pneumococcus, 



epidemics of the disease being sometimes due to this organism, 



and also by streptococci and staphylococci. True diphtheria of 



the conjunctiva 



caused by the 



Klebs-Loffler bac- 



illus also occurs, 



whilst in gonor- ^ ^ 



rhreal conjunctiv- 



itis, often of an JSm 



acute purulent 



type, the gonococ- ,*? 



cus is present (p. 



265). 



Diplo-bacillus of 



Conjunctivitis. - "V^\ 



This organism, dis- 

 covered by Morax, 

 is a small plump 

 bacillus, measuring N V 



1x2^, and usually ^^ 



occurring in pairs, 

 or in short chains of ' ' 



. -Koch-Weeks bacillus, from a young culture 

 agar ' Stained with weak ca ^ol-fuchsin. 



not form spores, and 



i -I'-ii 



is decolorised by 

 Gram's method. It 



does not grow on the ordinary gelatin and agar media, the addition of 

 blood or serum being necessary. On serum it forms small rounded 

 colonies which produce small pits of liquefaction ; hence it has been 

 called the bacillus lacunatus. In cultures it is distinctly pleomorphous, 

 and involution forms also occur. It is non-pathogenic to the lower 

 animals. 



Acne. In the pus of acne lesions and also in the comedoes a 

 bacillus of somewhat characteristic appearance may be found in 

 large numbers. The organism was first described by Unna and 

 afterwards cultivated by Sabouraud, and is now generally known 

 as the acne bacillus. It occurs in the form of short rods, some- 



