LI VINCI SPIROCHAETES 13 



twist of the body on itself and the coiling of one portion of the 

 organism round the other could be clearly seen on very careful 

 focussing. The looping of the body did not always occur at the 

 centre, for very often one part of the organism was seen to be 

 longer than the other (fîg. 11), and the shorter end was usually 

 the more indistinct one. The longer end often executed lashing 

 movements of a somewhat feeble character, but thèse became 

 more pronounced as the one part attempted to free itself from 

 the other. At times the looped portion seemed to become 

 thinner, suggesting that division miglit occur at that point, but 

 in no case was such division seen, though parasites in the above- 

 mentioned condition were watched continuously for many 

 hours. The usual resuit was that, after periods varying from a 

 few minutes (for example, seven) to several hours, the organism 

 completely uncoiled and swam away in a perfectly normal 

 manner. 



Undoubted longitudiiial division lias frequently been seen 

 in living S. haJhianii, S. anodontae, S. recurrentis and S. dut- 

 toni by Fantham and myself, and the process is essentially 

 the same in ail of thèse Spirochaetes. The fission commences 

 with the division of the basai granules into two, the division 

 of the membrane follows(fîg. 1), and waves rapidly pass do wn 

 thebody.The waves continue and the splitgradiiallyextends 

 towards the other end, until a figure resembling the legs of 

 a compass, figured by Fantham (I. 1908, p. 43, text-fig. 10) 

 or the arms of a Y is attained. The waves passing do wn the 

 arms vibrate in unison. The organisms remain in this condition 

 usually for a considérable time, but the split finally reaches 

 the further end, and the two daughter Spirochaetes separate 

 from one another, often remaining motionless for a short time 

 after the end of the division, before swimming away. 



When watching forms undergoing longitudinal division, 

 by no altération of focus was it possible to demonstrate two 

 c( bodies » in the unsplit part — one body only could be seen. 



Arguments hâve been advanced, by Swellengrebel and 



