PART III.] No Positive Evidence that the *' Refractive Bodies'' Germinate. 591 



If a very minute quantity of blood of this character be placed on a slide with a 

 little aqueous humor, it will be found that in the course of four or five hours, if the 

 temperature be about 90°, the bacilli will have grown very considerably, the majority 

 measuring 20 to 60/i-, and here and there in the preparation a filament may be 

 observed stretching half across the field of the microscope. A few hours later still, a 

 mesh-work of well-formed filaments will be manifest (Plate XLI, Fig. 2). Some of 

 these filaments will be found to be distinctly segmented, others apparently without a 

 single segment in their entire length, though even in these a tendency will be observed 

 to form more or less acute angles at certain distances. Other specimens will be found 

 to show traces of segmentation at either end or towards the middle. Drying the 

 specimen, or treating it with re-agents, will make the segments much more distinct. 



A few hours later some of the filaments will be seen to contain brightly refringent, 

 long-oval molecules, varying slightly in size, but l-2yii in length, by 1/x in width, may 

 be given as fair average dimensions. These are the " spores " which have been described 

 in Bacillus anthracis, etc. In a short time these refringent bodies dot the entire 

 length of the filaments, a tendency being manifested to present groups of twos along 

 the line. Grradually the filaments become more and more indistinct, until, finally, 

 only the more or less distinctly linear arrangement of these refringent bodies remains 

 to indicate the path of the filament (Plate XLI, Fig. 3). 



I have spent many hours, days even, in watching isolated molecules of this kind, 

 but have never been able to see anything which would warrant my saying positively 

 that they germinated : I can only support what Nageli, de Bary, and others have 

 persistently affirmed, namely, that the Schizomycetes multiply by fission only. The 

 bodies described and figured as germinating by Cohn, Koch, and others (Figs. 41, 42, 

 page 574), may be seen in most preparations, some of which will be found figured by 

 myself in Plat]e XLI, Fig. 5, but, so far as my experience goes, none of the objects 

 delineated represent the germination of " spores " or conidia ; certainly, here and there, 

 bodies may be seen which at first sight appear very like it, — such, for example, as the 

 refringent molecule figured at 5 a, as seen by Powell and Lealand's xV^b immersion, 

 — but frequently the extremely translucent filament attached to it extends beyond 

 the " spore " at either end (Fig. 5 b), thus showing that the filament is not formed 

 of plasma which had proceeded out of the spore, but is, in reality, a tube enveloping 

 it. It has been observed already that the observers who maintain that these refractive 

 bodies germinate, base their opinions on different grounds. Their figures in most 

 cases agree, but their interpretations differ. 



It may be suggested that, although the bacilli found in the decomposing blood 

 of healthy animals do produce spores, they are not of the same character as the spores 

 found in Bacillus anthracis. To this it may be replied that Cohn states that the 

 spores in the latter are identical in appearance and run through the same develop- 

 mental stages as the spores of the Bacillus subtilis of hay-solutions, so that the remarks 

 which I have ventured to make regarding the " spores" of the bacillus of ordinary blood 



