418 GLANDERS, ANTHRAX, PYOCYANEUS 
this phase of the subject are representative. An aggkitination with 
B. abortus in a dilution of 1 to 50 was obtained with the sera of 526 
out of a total of 535 apparently healthy cows; in the remainder (9) 
agglutinations took place in dilutions greater than 1 to 50. Of 127 
cattle, either infected or suspects, an agglutination was not obtained 
in a dilution of 1 to 50; in 11 agglutination was positive, 1 to 50; in 
19 a positive reaction was obtained in a dilution of 1 to 100; and in 
20 a reaction in a dilution of 1 to 200. Holth^ tested the sera of 7 
normal cattle with negative results. The sera of 38 animals out of a 
total of 39, which were plainly infected with B. abortus, gave positive 
agglutination with the specific organism in a dilution of 1 to 100. 
The method of complement-fixation, precipitin test, ophthalmo reac- 
tion and intracutaneous reaction with various preparations of B. 
abortus have been tested for their diagnostic value, but the results 
are not clear cut and definite. - 
In the light of Evans' work (p. 416) the immunological reactions 
should be tried with B. bronchosepticus and Bacillus melitensis 
as well. 
Prophylaxis and Dissemination.— The infection of market milk with 
B. abortus focuses attention sharply upon the transmissibility of the 
organism to man. Definite details are lacking, but pasteurization of 
milk should remove all practical danger from this source. 
BACILLUS MELITENSIS. 
Historical.— The organism was discovered by Bruce. ^ 
Morphology.— B. melitensis is a very small oval bacillus, occurring 
singly or in pairs, rarely in short chains; the individual cells measure 
about 0.3 to 0.4 micron in diameter. Many observers declare the 
organism to be an ovoid coccus, a view which is clearly in accord with 
Bruce's description. Evans"* states that certain strains consist almost 
entirely of coccoid cells. The bacilloid form almost invariably pre- 
dominates in fresh material. The organism is non-motile, possesses 
no flagella and forms no capsule. Spore formation has never been 
observed. It stains readily with ordinary anilin dyes, and is Gram- 
negative. Evans believes that B. melitensis and B. abortus are varie- 
ties of the same bacterial species. 
Isolation and Culture.— One of the noteworthy cultural characters 
of B. melitensis is its slow growth on artificial media, even at 37° C. 
Suspected material, either blood, urine, milk or material from splenic 
puncture, should be spread upon the surface of slightly acid agar and 
examined after three or four days' incubation for very minute white 
colonies which have a darker center. The organism grows slowly in 
1 Berl. tierartzl. Wchnschr., 1909, p. 680. 
2 See Klimmer (Ergebnisse der Immunitatsforsch. u. experimentelle Therap., 1914, 1, 
143-188) for details. 
3 Practitioner, September, 1887, 39, 161. 
" Public Health Reports, 1923, 38. 1943. 
