392 TIMOTHY RICHARDS LEWIS. 



bell-glass, evaporation was prevented. Not much change has 

 taken place, except that here and there is seen that some of the 

 ' spores ' within the filaments present a longer appearance, and 

 have become correspondingly narrower. In some a constriction 

 is seen, and others are completely divided and form two com- 

 plete molecules (PI. XVII, fig. 8) . In some instances the mole- 

 cules had become separated. [Compare with Dr. Ewart's figure 

 of Bacillus anihracis, fig. 8.] That the refringent particles were 

 in reality the ' spores ' of the previously distinctly seen filaments 

 was evident from the circumstance that, although the hyaline tube 

 which contained them was extremely translucent and only with 

 difficulty brought into view, still it was sufficiently strong to be 

 able to retain these refractive molecules in a row ; any movement 

 communicated to one part of the row was seen to be accompanied 

 by movement of the entire series. The movements were caused 

 by the constant agitation of objects in the field on account of 

 the presence of Bacterium iermo.'" 



No further change could be detected in the ' spores.' 

 The foregoing description, though applying to the more gene- 

 rally observed appearances which bacillus growths present, is by 

 no means the only course taken by such organisms when trans- 

 ferred to nutritive media other than that in which they were 

 developed, nor is it by any means a matter of certainty, at start- 

 ing, what particular course will be followed by them. In illus- 

 tration of this and also of the fact that, occasionally, exceptionally 

 large bacilli are to be found predominating in the blood (just 

 as we have seen to be the case with regard to exceptionally small 

 ones), the following extract from my note book may be instruc- 

 tive : — A rat which had been killed at 10 o'clock in the morning 

 was dissected at 5 in the afternoon of the same day. The tem- 

 perature had been about 94° F. The heart was carefully taken 

 out and a minute quantity of blood transferred, on the tip of a 

 scalpel, to a slide. A small quantity of a half per cent, solution 

 of salt and distilled wat^r was added, in order to dilute the 

 pveparation, and, by separating the corpuscles, render it easier 

 to see any foreign matters that might exist in the serum. There 

 were numerous motionless bacilli varying from 4 to 20 ^ in length 

 by "8 to 1'4 ju in width, the thicker variety predominating (PI. 

 XVII, fig. 9). The majority consisted of short stiS' rods, 5'5 /n 

 in length, or double this length ; in the latter case often manifest- 

 ing indications of a tendency to bend towards the centre. There 

 were also a few thicker rods than these scattered throughout 

 the preparation. An hour having been spent in the examina- 

 tion of this slide, it became apparent that the bacilli were more 

 numerous on it than when the examination commenced. It was 

 then set aside in a moist chamber. 



A similar slide was prepared, consisting of just a trace of the 



