460 HEMOGLOBINOPHILIC BACILLI 
3. Scrolofi leal. —The sera of animals highly immunized to the Bordet- 
Gengou bacillus are said to agglutinate the organism in high dilution, 
but fail to agglutinate the Pfeiffer bacillus and vice versa. The serum 
of patients during and after recovery from whooping cough, however, 
agglutinates the Bordet-Gengou bacillus irregularly, and the method 
has no general diagnostic importance. The method of complement- 
fixation similarly has not been successful as applied to the diagnosis of 
the disease in man, although the reaction is clear-cut when applied to 
the sera of immunized animals.^ 
The etiology of whooping cough has not been definitel^ established; 
the Bordet-Gengou bacillus, however, is found in a majority of cases 
of pertussis. Up to the present time it has not been isolated from 
healthy subjects. 
THE KOCH-WEEKS BACILLUS. 
Acute contagious conjunctivitis or, as it is popularly known, pink- 
eye, is generally considered to be an infection of the conjunctiva by 
a small bacillus first described by Koch.- Somewhat later Weeks^ 
described the organism anew and succeeded in growing it in artificial 
media, probably in association with other organisms. Kartulis'* 
isolated it in pure culture on blood serum, and Kamen^ published a 
more complete study of the cultural characters of the organism. 
Morphology.— The Koch- Weeks bacillus is a small rod-shaped 
organism resembling the influenza bacillus. It is of about the same 
diameter as the influenza bacillus, 0.25 micron, but somewhat longer, 
measuring from 1 to 2 microns in length. It occurs singly and in 
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. Five-tenths 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 conjimctiva 
thoroughly with sterile salt solution, then removing some of the secre- 
tion which soon accumulates with a sterile swab which is immediately 
rubbed upon the surface of the blood agar. x\fter twenty-four to forty- 
eight hours' incubation at 37° C. colonies usually appear which are very 
minute and colorless. They die rapidly, although cultures remain 
viable for about a week in human serum kept at 37° C. 
^ Wollstein: Loc. cit. 
2 Wien. klin. Wchnsclir., 1883, p. 1550; Arb. a. d. kais. Gesamte, 1887, 3, 19. 
3 Arch. Ophthalmol., 1886, 15, No. 4; Arch. f. .\ngenheilk., 1887, 17, 318. 
^ Centralbl. f. Bakteriol., 1887, 1, 289. 
5 Ibid., 1899, 25, 401, 449. 
