BRIEF NOTES ON SPIROCH.ETA ANODONT.E KEYSSELITZ. 391 



lowing observation supports the view that the change is, in 

 some cases at leasts one of development. 



A piece of crystalline style was dissolved in tap-water and 

 sealed up with vaseline for forty-eight hours under a cover- 

 slip on a slide. At the end of this period the cover was 

 removed, and the preparation was fixed in osniic vapour and 

 stained with thionine. The spirochastes, which had originally 

 been very numerous, were found to have almost entirely dis- 

 appeared, while their place was taken by elongated, variously 

 curved bodies, closely corresponding with them in length and 

 thickness, containing irregular masses of staining substance 

 (figs. 19 and 20). Some definite spirochietes present showed 

 beading of protoplasm and separation into segments (segmen- 

 tation, plasmolysis ?), and it was possible to trace a fairly 

 definite series of gradations between such spirochfetes, as 

 seen in this and other preparations, and strings of bead-like 

 or coccoid bodies, which seemed to constitute the final stage 

 of development (figs. 16, 18, 21, 22). It seems then that 

 Sp. anodonto3 goes through a stage in development in 

 which it breaks up into coccoid bodies, just as, according to 

 Leishman, Sp. duttoni breaks up into similar bodies inside 

 the body of the tick. If this be so we have, on the one 

 hand interesting evidence of the generic unity of the small 

 and large spirochetes, and on the other, of the affinity of 

 the whole group with the Bacteria rather than with the 

 Protozoa. 



The portion of style used for the above observation was 

 taken from a mussel which had been kept at a temperature 

 just above freezing-point. The spirochaetes seemed specially 

 numerous and lively at this temperature, and dividing forms 

 were numerous. I also found some organisms in the water 

 in which the mussels were kept. Most oi: these were stiff 

 and motionless, but one or two individuals were actively 

 moving Avhen first seen. The addition of water to a piece of 

 the style seems to have the effect of rendering a large number 

 of the organisms motionless and rigid (fig. 23), and it is 

 tempting to speculate as to whether the difference between 



