MICROCOCCUS LANCEOLATUS. 503 



to restore this virulence, or to keep it from becoming 

 attenuated, it is necessary, therefore, to interrupt the 

 transplantation and pass the organism through the 

 bodies of susceptible animals. 



With the view of overcoming some of these obstacles 

 in the way of cultivating this micrococcus, several spe- 

 cial media have been proposed by various experimenters 

 in the place of the ordinary culture media. The best 

 fluid medium for the growth of the pneumococcus is 

 Marmorek's mixture, consisting of bouillon, 2 parts ; 

 ascitic or pleuritic fluid, 1 part. In this fluid pneumo- 

 cocci grow well, and cultures when preserved in a cool 

 place and prevented from drying retain their vitality 

 and also their virulence for a number of months. 

 Lambert has found cultures in this medium alive and 

 fully virulent after eight months. 



Loftier 7 s blood-serum mixture is probably the best 

 solid tube medium for making cultures, and is very 

 convenient and useful at autopsies. One and one-half 

 per cent, fluid nutrient agar mixed with one-third its 

 quantity of warm ascitic fluid makes an excellent plate 

 medium. 



Effects of Germicidal Agents, Light and Drying. The 

 following are the effects of germicidal and antiseptic 

 agents on this organism, according to observations 

 made by Sternberg : Boric add, saturated solution, 

 failed to destroy the vitality after two hours, but a so- 

 lution of 1 : 400 restrained its development; carbolic 

 acid, 1 per cent, solution, destroys the vitality in two 

 hours, and 1 : 500 restrains development; mercuric chlo- 

 ride,! : 20,000, destroys vitality in two hours,! : 40,000 

 restrains development; salicylic acid and sodium bibo- 

 rate, 1 : 400 solution, restrained development. 



