472 ('. CLIFrOKD DOLIELL. 



Again in this organism, staining resnlts confirm the morplio- 

 logical interpretation. 



Arguing now on analogy, it becomes liiglily probable that 

 the scattered granules of Bacilli of the flexilis type — ^the 

 chromidia, in other words — -are of the same nature as the 

 granules of Bacillus saccob ranch i. They are the only 

 morphological elements distinguishable in the cells, and that 

 they are living structures — not reserve material — appears to 

 me quite certain from the part which they play during spore- 

 formation. When it is further found that, in the course of 

 spore-formation, the granules arrange themselves in the form 

 of a spiral or zig-zag filament^ — like that of Bacilli of the 

 spirogyra type — then the nuclear interpretation of the 

 granules is not merely strengthened, but becomes almost a 

 certainty. It appears to me that there is only one logical con- 

 clusion to be drawn from these facts — that the chromidia of 

 Bacilli of the flexilis type represent the nucleus, 

 being the equivalent (morphologically) of the spherical 

 nucleus of Cocci and of the spiral filament of other Bacilli. 



When we find that many smaller Bacilli show a structure 

 which is essentially the same as that of the large Bacilli of 

 the flexilis type, it is only natural to suppose that we see 

 here, also, structures which are capable of a similar inter- 

 pretation. The assumption is justified that the chromidia 

 of small Bacilli constitute their nuclear apparatus. 



In all these cases, moreover, staining reactions — so far as I 

 have tried them — support the morphological interpretation. 



It" we now consider the structures which are present in the 

 Bacilli of a modified flexilis form (from the newt and 

 lizard — see p. 430) it becomes apparent that these structures 

 also represent phases of the nuclear apparatus. The actual 

 facts here are not so well established as in the forms which I 

 have hitherto considered^ but it is at least exceedingly 

 ))robable that in these the nucleus exists, at some stages in 

 the life-history, in the form of a few large globular masses. 



' Discovered by Scluuidimi (1902) in Bacillus biitschlii, and 

 confirmed by me (1908) in the case of B. flexilis. 



