300 BACTERIOLOGY. 



attempt. So uncertain is its growth under artificial 

 conditions that it is always advisable to inoculate a 

 number of tubes with relatively large quantities of the 

 exudate, and even then growth often occurs in only a 

 part of them, notwithstanding the fact that on micro- 

 scopic examination the organism may have been readily 

 detected in large numbers in the exudate. Illustrative 

 of this difficulty, the following experience of Council- 

 man, Mallory, and Wright may properly be quoted: 1 



"As showing the difficulty in growing the organisms 

 in cultures made from the meninges at the post-mortem 

 examination, ten cultures were made in one case from 

 the exudation on the brain and six from the cord, cover- 

 slip examinations showing abundant organisms in the 

 cells. Only two of the cultures from the brain and one 

 from the cord showed a growth. As a rule, the organ- 

 isms were more easily obtained in cultures made from 

 the acute cases than from the chronic." 



When successfully isolated in pure culture its growth 

 is never profuse on any medium. On the serum mixt- 

 ure of Loftier the isolated colonies appear as round, 

 viscid, smooth, sharply defined points that may attain 

 a diameter of 1 to 1.5 mm. There is no liquefaction 

 of the medium. Cultures from very acute cases occa- 

 sionally present an abundant growth of fine, transparent 

 colonies strongly suggestive of those of micrococcus 

 lanceolatus. 



On glycerin-agar the colonies are round, pearly, trans- 

 lucent, flat, and viscid in appearance. They tend to 

 become confluent. Under low magnifying power they 

 are homogeneous, semitransparent, faintly brownish, 



1 See " Epidemic Cerebrospinal Meningitis," etc., Report of the State 

 Board of Health, Mass., 1898, by Councilman, Mallory, and Weight. 



