256 MANUAL OF BACTERIOLOGY. 



cultures on a number of occasions. The disease may be 

 reproduced in monkeys by inoculation with pure cultures. 

 An agglutination reaction occurs in this disease. The 

 diagnosis is best made by applying this test to the blood- 

 serum of the patient, with a known pure culture of micro- 

 coccus melitensis. 1 A suspension of an agar culture is 

 made in normal salt solution. The diluted serum is added 

 so as to secure a dilution of about i to 50, but the dilutions 

 used have varied widely. Precipitation quickly occurs. 

 According to Craig the test may be made on a slide, examin- 

 ing with the microscope as for the typhoid bacillus (see 

 Serum-test for typhoid fever). 



Diplococcus intracellularis meningitidis. 2 Found in the 

 exudate of cerebro-spinal meningitis by Weichselbaum ; a 

 micrococcus about the size of the common pyogenic cocci ; 

 grows in pairs or fours, more often in pairs consisting of 

 two hemispheres separated by an interval which does not 

 stain ; usually found within the pus-cells, in which respect it 

 resembles the gonococcus. It is stained by ordinary methods 

 with the aniline dyes, and is decolorized by Gram's method. 

 It does not grow at the room temperature but only in the 

 incubator; gelatin is not available. There is no growth on 

 potato and scanty growth on agar or in bouillon. The 

 development is most abundant upon Loffler's blood-serum, 

 when round, white, shining, viscid-looking colonies with 

 sharp outlines may be seen in twenty-four hours. The 

 serum is not liquefied. Upon agar, or better upon glycerin- 

 agar, the colonies are flat, round, translucent, viscid-look- 



1 Mtisser and Sailer, PhiladelpJiia Medical Journal, December 31, 1898, 

 July 8, 1899; Strong and Musgrove, Ibid., November 24, 1900; Curry, 

 Journal Medical Research, Vol. VI., 1901. 



2 The writer is indebted for the brief statement, which it is possible to 

 give here, chiefly to the exhaustive Report to the Massachusetts Board 

 of Health by Councilman, Mallory and Wright, 1898. The photograph 

 was made from a preparation kindly furnished by Dr. Mallory. 



