PNEUMONIA. 289 



gelatin to form white masses of a considerable size. 

 Under the microscope these colonies are rather irregular 

 in outline and somewhat granular. 



The bacillus grows at as low a temperature as 16 C, 

 and, according to Sternberg, has a thermal death-point 

 of 56 C. 



When a colony is transferred to a gelatin puncture-cul- 

 ture, quite a massive growth occurs. Upon the surface a 

 somewhat elevated, rounded white mass is formed, and 

 in the track of the wire innumerable little colonies 

 spring up and become confluent, so that a " nail-growth " 

 results. No liquefaction occurs. When old the cultures 

 sometimes become brown in color. 



Upon the surface of agar-agar at ordinary temperatures 

 quite a luxuriant white or brownish-yellow, smeary, cir- 

 cumscribed growth occurs. The growth upon blood- 

 serum is the same. 



Upon potato the growth is abundant, quickly covering 

 the entire surface with a thick yellowish-white layer, 

 which sometimes contains bubbles of gas. Gas is also 

 sometimes developed in gelatin cultures. 



A most superficial comparison will suffice to show the 

 great difference in vegetation between these two so-called 

 pneumococci. 



Friedlander had considerable difficulty in causing any 

 pathogenic changes by the injection of his bacillus into 

 animals. Rabbits and guinea-pigs were immune, and 

 the only actual pathogenic results which Friedlander ob- 

 tained were in mice, into whose lungs and pleura he 

 injected the cultures. 



In the status prcesens of bacteriologic knowledge the 

 bacillus of Friedlander is regarded as an organism, 

 generally a harmless saprophyte, but at times capable of 

 producing inflammations. 



Curry 1 has found Friedlander' s bacillus in combina- 

 tion with the pneumococcus in acute lobar pneumonia, 



1 Journal of the Boston Society of Medical Sciences, March, 1898, vol. ii., 

 No. 8, p. 137. 

 19 



