(Trypanosoma) Balbianii and S. anodontae. 499 



and is probably the locomofor agent of the organism. Its 

 own vibrations are very slight, and by its alternate contrac- 

 tion and expansion it appears to control the movements of 

 the organism. The structure and function of this "organella" 

 are most dijficuh to interpret. The myoneme?i, I think, set 

 up transverse movements in the surface of the body, manifested 

 as waves passing down the body in a direction opposite to 

 that in which the organism progresses. 



It has been stated that the nuclear core is contractile 

 (Swellengrebel [lo]). I am rather inclined to the view that 

 it is only flexible. 



It has been suggested [i i] that there is a ciliate stage in 

 the life-history of S. Balbianii — in other words, that the 

 membrane is built up from the agglutination of cilia 

 (" flagella " of English bacteriologists), or even that the 

 membrane may be decomposed into these flagella. I have 

 myself preparations of this character made both at RoscofF 

 and in London. It seems to me that these apparent flagella 

 or cilia are really elastic filn-ils^ staining ])ink with Giemsa's 

 or Leishman's stain, " myoneme fibrils" in fact, split off 

 from the membrane during its rupture, which sometimes 

 occurs during the violent contortions and death-struggles of 

 the organism, especially in a damp atmosphere like that of 

 Koscoff. It may be that the membrane, as suggested in a 

 private communication, is really a " ciliated membrane.'' I 

 have never seen these flagella during life. 



The fibrillar nature of the membrane is none too well 

 shown by the various modifications of the Romanowsky 

 stain. It is best revealed by gentian-violet or iron- 

 hjematoxylin. 



In life, during active movements, the membrane is closely 

 contracted round the body, and is not easily seen except as a 

 halo round the organism. 



The membrane of S. anodontce is most difficult to discern, 

 but it can be seen in favourably placed specimens both in 

 life and when stained. It appears to conform to the structure 

 described for S. BaUdanii. 



Division. 



Longitudinal division has been described before in the case 

 of these Spirochaetes. I have seen such during life and in 

 stained preparations. 



However, I believe transverse division also occurs, for in 

 the case of 6'. Balbianii both long and short forms are seen. 

 In some stained preparations there were somewhat long forms 



