478 PATHOGENIC BACTERIA. " a line of finely granular, non-liquefying colonies. Upon the surface of the gelatin the growth expands so*as to form the so-called u nail-growth." The colonies upon gelatin have an irregularly circular form, appear white or straw-yellow by reflected light and olive-green by transmitted light, and are granular. They do not liquefy and do not grow to large colonies. In bouillon after twenty-four hours there was a faint clouding of the liquid and subsequently a sedimentation of the bacteria in small clusters. After a week or so the surface of the medium is covered with a delicate pellicle, which grows thicker with the passage of time. The bacillus grows quite well anaerobically. It is motile. The bacillus is pathogenic for mice, but does not pro- duce characteristic symptoms in any of the experiment- animals. In discussing the results of Koplik's work, and com- paring it with their own, which very shortly preceded it, Czaplewski and Hensel suggest that the bacillus is better described as a bacterium than as a bacillus. The finely granular ("fein punktiertes ") appearance described by Koplik, in their observations seems to consist of a deeper staining at the poles of the cells. The growths on gelatin and on Loftier's blood-serum mixture correspond in every way. The agar-agar growths are similar, though a slight difference in color is noted, and is attrib- uted to a difference in the quality of the medium used. The bouillon culture differs, the description of Czaplewski and Hensel being as follows: at the end of a day at 37° C. the bouillon is scarcely clouded. At the bottom of the tube is a sharply defined, lentil-like sediment, which arises in the form of slimy threads when the fluid is whirled about, and mixes with the fluid when ener- getically shaken. Neither -bacillus grows on potato. Koplik's bacillus was also peculiar in that it was motile. Regarding Koplik's bacillus as identical with their own, Czaplewski and Hensel do not agree with him in believ-