752 Transactions of the Society. 



given by P. Geddes and J. Cossar Ewart, M.D., in the Proceedings 

 of the Royal Society, No. 188, 1878, it is shown that at one 

 term of existence, the screw-shaped rods become less twisted, and 

 finally straight, passing into the ordinary rod form as in Fig. 7, 

 given by them. They also suggest that the term Vibrio should 

 not be considered as generic. When examining the above-named 

 fluids I have repeatedly found many of the long spirilla motionless, 

 with one half having lost all twist except a large gentle curve, 

 but that end presented a very delicate pale, very finely granular 

 condition, differing entirely from the other part, the end being 

 scarcely visible even when stained, and I have regarded this as a 

 progressive dissolution of the organism. In the case I have men- 

 tioned we might have expected the spirilla to have reverted to rods, 

 which was not the case, so far as I could determine, and from the 

 Spirillum found in the goat excrement, appearing after and so 

 largely replacing the rods, I think it offers a fair plea that Bacillus 

 and Spirillum are to be considered distinct, though the latter, 

 when broken up, may greatly resemble bacillus rods. The straight 

 rods I should regard as Bacillus subtilis, and the curved ones 

 as merely an accidental variation in their form, though many with a 

 single curvature had very much the appearance of Vibrio rugula. 



In the same paper it is stated the parent or spore-bearing 

 hyphse are locomotive, "and the spores quiescent." The authors 

 say, "The life-history of Spirillum, so far as we at present know, 

 may be thus summarized. The well-known motile corkscrew may 

 alternate between the active and resting states, and ultimately 

 lengthen out into a small filament, which loses its definite twist, 

 and may freely bend or straighten. This thread grows into a 

 much larger and longer motionless filament in which spores appear. 

 These rapidly divide and acquire a bright brown colour, the 

 filament re-assuming the motile condition, and sooner or later 

 breaking up." 



The spiral organisms were rigid, with a spiral movement. In 

 size they appear rather smaller than the figures given of Spirillum 

 volutans, and larger than Spirillum tenue, approaching nearer 

 to the Vibrio serpens of Cohn. If the term vibrio were put aside, 

 would it not be as well to substitute for the curved forms of 

 Bacillus, Bacillus curvatus, or Bacillus subtilis var. curvatus, and 

 thus help to get rid of the objectionable term ? Having some doubt 

 as to the exact species of Spirillum, I have not given more than the 

 generic name. 



I found the organisms varied so considerably according as they 

 were left dry upon the cover-glass after or before staining, or 

 mounted in distilled water, or in a semi-saturated solution of acetate 

 of potash, or in dammar medium, that I have not given the measure- 

 ment. The one method of mounting would not agree with the 



