At present the need is felt for a simple medium for prolonging the viability of the meningococcus. A variety of mediums have been devised with this object in view, but generally they are prepared with difficulty, as in the cases in which animal blood is used, or they do not sustain the organism a sufficient time. In this communication a medium is presented which is simple to prepare and prolongs the viability of the meningococcus for at least a month.
Yeast contains elements necessary for bacterial growth and maintenance. Ickert1 found that certain organisms thrive on yeast peptone agar although free from meat infusion or meat extract. The following is an adaptation to the meningococcus of Ickert's findings, using a modified medium:
PREPARATION OF THE MEDIUM
Ten gm. of bakers' or brewers' yeast are macerated in 100 c.c. of water for twenty minutes, and the suspension is steamed for