THE GENUS SPIROCHETA AND ALLIES 



227 



hand, are equally positive that division here is transverse, Borrel, 

 Laveran, Zettnow, Koch, Novy and Knapp, Levaditi, Goldhorn, and 

 many others taking this view. Schaudinn and the Hungarian ob- 

 servers note that the greater part of the organism divides with great 

 rapidity, and that, as in Spirochcta halhiaml, the partly separated 

 daughter cells remain attached for a long period, and finally pull 

 apart as though dividing transversely (Fig. 90, G, H, I, J , M). The 

 advocates of transverse division, on the other hand, explain the 

 apparent longitudinal splitting as an illusion caused by the dividing 

 cells turning and twisting upon one another. No final decision can be 

 made at present; it is certainly difficult, on the basis of longitudinal 

 division only, to account for the strings of cells that are often found 

 with thinned regions, and skepticism regarding the schematic course 

 of events as given by Krzysztalowicz and Siedlecki cannot be wholly 



Fig. 91 



c 



D 



Spirocheta duttoni (Novy and Knapp). A,B,C, after Breinl, X 4500; D, after Carter; 

 j4,fi, spirochetes reproducing by transverse division; C, by loneitudinal division; Z), para- 

 sites from egg of Ornithodorus moubata with chromatoid granules divided equally and cell 

 bodies partly split. 



dispelled by their explanation of these strings as "colonies." If, like 

 Spirocheta halhianii, the organism of syphilis divides both longitu- 

 dinally and transversely, the catenoid colonies are easily interpreted. 

 Similarly with Treponema c/alllnanan, Sp. recurreuiis, and Sp. 

 duttoni, equally competent observers take diametrically opposite 

 sides regarding the j>lane of division. It is highly probable that 

 Sp. recurrent is of relapsing fever divides usually by cross-division, but 

 Carter's and Prowazek's observations on Sp. duttoni and Sp. cjaUi- 

 narum certainly show that lengthwise division occurs in these forms, 

 Carter ('()7) especially showing that the granules of chromatoid matter 

 within the cell are placed opposite one another in the divided daughter 

 halves (Fig. 91, D). 



