MICRO-ORGANISMS BELONGING TO THE HIGHER BACTERIA 419 



The characteristics of the micro-organism described by these workers 

 differed greatly and have led to confusion. Bostroem's organism grew 

 best aerobically and developed well at room temperature. He noted 

 the intimate relation of the organism with fragments of grain, and this 

 led to the finding of similar micro-organisms in the outer world on grains, 

 grasses, etc. 



There is no doubt that some suppurative processes have been due 

 to organisms of these characteristics, but they do not seem to excite 

 true actinomycosis. 



Wolf and Israel described a micro-organism from two human cases, 

 which differ from that described by Bostroem, but agrees with the micro- 

 organisms obtained by most of the more recent investigators. It grew 

 best under anaerobic conditions and did not grow at room temperature. 

 Its growth was much less luxuriant than Bostroem's micro-organism. 

 On the surface of anaerobic agar slant cultures on the third, fourth, and 

 fifth day numerous minute isolated dew-drop-like colonies appeared, the 

 largest pinhead in size. These gradually became larger and formed 

 ball-like, irregularly rounded elevated nodules varying in size up to 

 that of a millet-seed, exceptionally attaining the size of a lentil or larger. 

 As a rule the colonies did not become confluent, and an apparently 

 homogeneous layer of growth was seen to be made up of separate 

 nodules if examined with a lens. In some instances the colonies pre- 

 sented a prominent centre with a tabulated margin and appeared as 

 rosettes. A characteristic of the colonies was that they sent into the agar 

 root-like projections. In aerobic agar slant cultures no growth or a slow 

 and very feeble growth was obtained. In stab cultures the growth was 

 sometimes limited to the lower portion of the line of inoculation or was 

 more vigorous there. In bouillon, after three to five days, growth 

 appeared as small white flakes, partly floating and partly collected at 

 the bottom of the tube. Growth occurred in bouillon under aerobic 

 conditions, but was better under anaerobic conditions. The micro- 

 organism in smear preparations from agar cultures appeared chiefly as 

 short homogeneous, usually straight, but also comma-like or bowed 

 rods, whose length and breadth varied. In many cultures short clump 

 rods predominated, and in others longer, thicker, or thinner individuals 

 were more numerous. The ends of the rods often showed olive or ball- 

 like swellings. Some twenty guinea-pigs and rabbits were inoculated, 

 most of them in the peritoneal cavity, with pieces of agar culture. 

 Eighteen animals were killed after four to seventeen weeks, and four 

 were still alive seven to nine months after the inoculation. Seventeen 

 rabbits and one guinea-pig showed at the autopsy tumor growths mostly 

 in the peritoneal cavity and in one instance in the spleen. In the four 

 animals still living tumors were to be felt in the abdominal wall. The 

 tumors in the peritoneal cavity were millet-seed to plum size, and were 

 situated partly on the abdominal wall and partly on the intestines, the 

 omentum, the mesentery, and in the liver or in adhesions. While the 

 surface of the smaller tumors was always smooth, the surface of the 

 larger tumors showed small hemispherical prominences, giving them the 



