LIVING SPIROCHAETES 15 



connexité, il se constitue quatre nouvelles membranes avec un 

 point nodal au niveau de la séparation des deux individus. » 



I am sorry that I cannot agrée with the interprétation that 

 BoRREL has given. AU Spirochaetes are not provided with two 

 membranes, but only those about to divide. Also, the rapidity 

 of multiplication of Spirochaetes is well known. Dutton and 

 ToDD (1907), Fantham (1907) and Breinl (1907) hâve descri- 

 bed both transverse and longitudinal division of thèse organisms. 

 As already stated. I also bave seen both transverse and lon- 

 gitudinal division of the living Spirochaetes. Now, it not 

 infrequently happens, that a transverse division is succeded 

 very rapidly by a longitudinal one, the résultant four daughter 

 forms remaining in close proximity to one another. The appea- 

 rance of four membranes is thus produced. Fantham (I, 1908) 

 figured transverse division of S. halhimiii immediately followed 

 by the beginning of longitudinal division in his Plate 3, fig. 19. 



Regarding transverse division, Fantham and I hâve watehed 

 the entire process in living 8. anodontae, as well as in the Spiro- 

 chaetes of blood. Transverse division is initiated by waves 

 which pass from each end of the organism towards its middle. 

 Thèse waves meet at a point at or near the centre, which serves 

 as a node, about which division takes place. When the waves 

 meet, they die out and return waves pass outwards from the 

 node towards each end of the parasite. Thèse processes are 

 repeated many times, the Spirochaete increasing slightly in 

 length the while. At the same time each of the daughter forms 

 moves its body spirally, and reversai of the direction of the 

 hélix occurs, a right-handed hélix becoming a left handed one 

 and vice-versâ. A twisting strain is thus exercised upon the 

 node. Finally a succession of very rapid waves occurs, the 

 nodal région, which has been growing steadily more tenuous, 

 parts, and two complète daughter organisms are produced. 



Transverse division results in the formation of two daughter 

 organisms, equal or sub-equal in length, according as the node 

 about which division takes place is central or slightly excentric. 



