424 HEMOGLOBINOFHILIC BACILLI 



pairs, but short chains of bacilli are not uncommonly seen in growths 

 on artificial media. Involution forms, which are atypical in form and 

 size, are also found in cultures outside of the body. The organism is 

 non-motile and it has no flagella. Capsules and spores have not 

 been demonstrated. The Koch- Weeks bacillus stains with ordinary 

 anilin dyes, but not intensely. It is Gram-negative. 



Isolation and Culture. The organism grows best in a medium of 

 semi-liquid consistency. 5 per cent, agar containing blood or ascitic 

 fluid appears to be the best for this purpose. Material for inoculation 

 is conveniently obtained first by flushing the conjunctiva thoroughly 

 with sterile salt solution then removing some of the secretion which 

 soon accumulates with a sterile swab which is immediately rubbed 

 upon the surface of the blood agar. After twenty-four to forty-eight 

 hours' incubation at 37 C. colonies usually appear which are very 

 minute and colorless. They die rapidly. 



Resistance. The Koch- Weeks bacillus is very susceptible to drying 

 and to heat; chemical disinfectants very rapidly destroy the organism 

 outside the human body. 



Nothing is known of the products of growth. 



Pathogenesis. Attempts to produce conjunctivitis in animals with 

 the organism have been uniformly negative but inoculations upon 

 the healthy conjunctiva of man usually reproduce the disease. 



The disease is very contagious; it is spread chiefly by contact. 



MORAX-AXENFELD BACILLUS. 



In 1896 Morax 1 described a diplobacillus which he observed repeat- 

 edly during an epidemic of subacute conjunctivitis. The year follow- 

 ing, Axenfeld 2 published an excellent description of the same organism, 

 which is commonly referred to as the Morax-Axenfeld bacillus or the 

 diplobacillus of subacute conjunctivitis. 



Morphology. The organisms, as the name implies, occur typically 

 in pairs; less frequently they may remain adherent to form short 

 chains. The individual bacilli are of average size, measuring from 

 1 to 2 microns in length, and about 1 micron in diameter as an average. 

 The ends of the bacilli are rather square cut. Cultures on artificial 

 media are somewhat variable in size and shape; chain formation is not 

 uncommon and involution forms are frequent. The organisms are 

 non-motile and possess no flagella. Neither spores nor capsules have 



1 Ann. Inst. Past., June, 1896. 2 Centralbl. f. Bakt., 1897, xxi, 1. 



