COCCACE.E AND THEIR PARASITIC RELATIONSHIPS 263 



blood with distilled water and adding this to melted glucose agar 

 in a quantity sufficient to give it a pink tint. The color of blood 

 is unaltered by the growth. Cultures may be obtained on Loffler's 

 blood serum, although this medium is not very satisfactory for 

 this purpose. The meningococcus grows more luxuriantly than 

 the gonococGUs, as a rule, and adapts itself more readily to growth 

 on ordinary media, but its cells disintegrate rapidly in the colony, 

 which is viscid. In nearly every respect it resembles very closely 

 the gonococcus. 



Intraperitoneal inoculation of white mice and of guinea-pigs 

 usually results in fatal peritonitis and the organism can be recov- 

 ered from the heart's blood. Intraspinal inoculation of monkeys 

 with large doses causes typical meningitis with symptoms similar 

 to those of the disease in man. In man the disease is undoubtedly 

 transmitted very largely by coccus-carriers, healthy people or 

 people with slight pharyngitis or rhinitis, who carry the virus on 

 their mucous membranes and distribute it. 



Several serologically different -types of meningococci are 

 recognized and for the specific recognition of the meningococcus 

 by the agglutination test, it is advisable to employ polyvalent 

 serum as well as the various mono-valent sera in dilutions of i 

 to 100 and I to 200. Suspensions of living cultures grown on plain 

 agar or on serum agar, if necessary, are mixed with the serum and 

 the tubes are incubated 16 hours at 55° C. A control tube of 

 normal serum should be included in the test. 



Ordinarily, specific agglutination and type determination may 

 be neglected in the recognition of meningococci found in the 

 cerebro-spinal fluid. When isolated from the pharynx, bronchi 

 or lungs, confusion with other organisms is more probable and, in 

 these instances, agglutination tests are required. Bacteriologists 

 undertaking this work should consult the paper of Flexner^ and 

 the Uterature there cited, especially the Gordon report. 



Antimeningococcus serum is prepared by immunizing horses 



1 Flexner, S.: Mode of infection, mears of prevention and specific treatment 

 of epidemic meningitis, Journ. Amer. Med. Assn., 1917, 69, p. 639, p. 721, p. 817. 



