682 A MANUAL OF BACTERIOLOGY 



The organism does not stain by Gram's method, and can be 

 cultivated on blood agar, on which it forms shining greyish colonies 

 1 mm. in diameter, or in guinea-pig blood. 1 Keenstierna has 

 obtained an anti- serum by inoculating rams with dead and living 

 cultures. Tested in 100 cases, the anti-serum produced improve- 

 ment and cure within a short time, except in seven of the cases, 

 which were shown to be due to infection with staphylococci. 

 CONJUNCTIVITIS. Conjunctivitis is of several varieties : 



(a) Acute contagious conjunctivitis, due to the Koch-Weeks 

 bacillus. This is a slender, non -motile organism, 1-1-5 p. in 

 length, occurring singly or in pairs, both free and within the pus- 

 cells. It is decolorised by Gram's method, and is difficult to 

 cultivate, growing best on a serum -agar mixture, on which it 

 forms small, punctiform transparent colonies. It is hardly 

 pathogenic to animals, but in man sets up a typical acute con- 

 junctivitis. 



(b) Chronic catarrhal conjunctivitis, due to the Morax-Axenfeld 

 diplo -bacillus. This organism is 2 /z long by 1 p. broad, is not 

 stained by Gram's method, and can be cultivated on blood-serum, 

 which becomes pitted from liquefaction, or on serum agar, but 

 not on ordinary agar nor on gelatin. Petit described also a closely 

 allied organism distinguished by its ready growth on agar and 

 on gelatin, which is liquefied. 



(c) Oonorrhceal conjunctivitis. 



(d) Diphtheritic conjunctivitis. 



(e) Conjunctivitis of streptococcic origin. 



(/) Conjunctivitis of pneumococcic origin. Usually in children, 

 and accompanied with coryza and scanty muco -purulent discharge. 



(g) Micrococci (aureus and albus) and B. coli may also occa- 

 sionally cause conjunctivitis. 



DIARRHCEA (SUMMER) OF INFANTS. Lesage obtained a bacillus 

 from the " green diarrhoea " of infants which he believed to 

 be the cause of this complaint. It is a small, motile, non-lique- 

 fying bacillus, producing on gelatin a whitish expanded growth 

 with crenated margins, and giving rise to a green fluorescence 

 in the medium. The B. pyocyaneus may be an occasional cause. 



In cases with blood and mucus in the stools, the B. dysenteries 

 (Shiga-Kruse type) has been found to be present in America but 



1 Himmel, Ann. de Vlnst. Pasteur, xv, 1901, p. 928. 



