MICROCOCCUS LANCEOLATUS. 501 
action of germicidal agents. Its pathogenic power also 
undergoes attenuation very rapidly when cultivated on 
artificial media. It is non-motile. 
_ In the cultivation of this organism one of the most 
important considerations is the reaction of the media 
employed. According to Fraenkel, Sternberg and 
others, it grows only in culture media when they have 
a slightly alkaline reaction. Kruse and Pansini showed 
by their investigations that, according to the source 
from which it was obtained, it grows at times equally 
well in a slightly alkaline or slightly acid medium. 
Not infrequently, however, all experimenters have 
found that no growth at all occurs, irrespective of the 
composition or reaction of the media employed. The 
weight of opinion, nevertheless, seems to be in favor of 
the selection of a slightly alkaline medium. 
The organism grows, as has been said, on all the cul- 
ture media ordinarily employed for the cultivation of 
bacteria—viz., on agar and gelatin, in bouillon, ascitic 
fluid, and blood-serum. The best medium for its 
growth is a mixture of one-third ascitic or pleuritic 
fluid and two-thirds bouillon. It grows readily in 
milk, causing coagulation with the production of acid, 
though this is not constant. 
Growth on Agar. Cultivated on plain nutrient agar, 
after forty-eight hours in the incubator, there ap- 
pears a thin, colorless layer composed of dilute non- 
confluent colonies. If blood-serum or ascitic fluid be 
added to the agar the individual colonies are larger and 
closer together, and the growth is more distinct in con- 
sequence and of a grayish color. The surface colonies 
resemble those of some of the streptococci growing in 
short chains; they are almost circular in shape, finely 
