PART III.] Appearances which Baciflus Growths present under Cultivation. 593 



formed in each segment, the joint being still faintly visible, but the plasma disappeared 

 except at one or two parts — generally the end-segments of a thread (d). Commonly 

 the separated segments contained two ' spores,' presumably coinciding with the original 

 number of segments. The threads are wider w^hen containing 'spores' than previously. 

 The 'spores' = 1 to l*4/x, in length, by '8 to 1/^ in breadth. The space allotted to 

 each ' spore ' in a filament, presumably each segment, was from 6 to 7/a in length, so 

 that a filament containing two ' spores ' would = 12 to 14/x, and three ' spores ' = 18 

 to 21/A, and so on, so that the filament manifestly swells out in all directions." 



The third day ; " Having set the slide in moist air under a bell-glass, evaporation 

 was prevented. Not much change has taken place, except that here and there it 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 minute molecules (Plate XLI, Fig. 8). In some instances 

 the molecules had become separated. [Compare with Dr. Ewart's figure of bacillus 

 anthracis, Fig. 44, page 575.] 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 

 bacternim termo." 



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



The foregoing description, though applying to the more generally observed appear- 

 ances which bacillus growths present, is by no means the only course taken by such 

 organisms when transferred to nutritive media other than that in which they were 

 developed, nor is it by any means a matter of certainty, at starting, what particular 

 course will be followed by them. In illustration 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 instructive : — " A rat which had been 

 killed at ten o'clock in the morning was dissected at five in the afternoon of the 

 same day. The temperature 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 water was added, in 

 order to dilute the preparation, and, by separating the corpuscles, render it easy to 

 see any foreign matters that might exist in the serum. There were numerous motion- 

 less bacilli varying from 4 to 20/i, in length, by -8 to 1-4/^ in width, the thicker variety 

 predominating (Plate XLI, Fig. 9). The majority consisted of short stiff rods, 5-5fi in 

 length, or double this length ; in the latter case often manifesting indications of a 

 tendency to bend towards the centre. There were also a few thicker rods than these 



40 



