360 APPLICATION OF METHODS OF BACTERIOLOGY 



two of the cultures from the brain and one from the cord 

 showed a growth. As a rule, the organisms 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 mixture of 

 Loffler 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 occasionally 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 homo- 

 geneous, semitransparent, faintly brownish, with well-defined 

 smooth margins. On plain agar the growth is feeble and 

 uncertain. 



Its growth in bouillon is slow and uncertain. It does not 

 cause clouding of the fluid, but collects at the bottom of the 

 tube as a scanty grayish sediment, that when disturbed 

 gives the impression of having a mucoid consistency. 



It does not grow on potato and causes no change in litmus- 

 milk. 



It grows only at the temperature of the body, and can 

 be kept growing only by being transplanted to fresh media ' 

 about every two days, and even then growth often ceases 

 after a comparatively small number of transplantations. 

 If from a fresh growing culture a number of tubes be inocu- 

 lated and kept under favorable conditions, it is a common 

 experience to have growth on only a part of them. It is 

 sometimes impossible to obtain a second growth on agar-agar. 



