LIVING SPIROCHAETES 3 



in a few of the Molluscs I found a large Spirocliaete, hitherto 

 undescribed. 



Similarly, spécimens of Sphaeriimi corneum were examined, 

 and a new and smaller Spirochaete was found tlierein. 



Both 8. anodontae and S. haïbianii were examined carefully 

 by varions means and under différent conditions, and compa- 

 rison of their movements was made with those of the Spiro- 

 chaetes of Ta'pes (a paper on which, by D^" Fantham, will 

 sliortly appear), and with those of new Spirochaetes from 

 Mytilus and Sphaerium, on which I hope to pubHsh soon. 



In an endeavour to get further information, use was made 

 of the most récent aid to zoological research, the ultra-micros- 

 copic (paraboloid) sub-stage condenser, and the information so 

 obtained was not only most interesting in itself , but proved a 

 most vahiable help in studying the Spirochaetes. Another 

 most useful aid was the examination of hving material 

 under the water-immersion lens (2.5 mm.apochromat of Zeiss), 

 and this gave some very fine results, particularly with regard 

 to the structure of the membrane. 



I hâve attached spécial importance to the study of Spiro- 

 chaetes in vivo. My results may now be set forth under appro- 

 priate headings. 



III. — Morphology. 



The hody of Spirochaeta haJhianii (fig. 1, h) lias two rounded 

 ends, wliile that of 8. anodontae lias pointed ones (figs. 3 to 7). 

 According to some writers, who consider Spirochaetes to be 

 Bacteria and not Protozoa, the pointed ends should be flagella. 

 I can state, with absolute confidence, that I hâve ne ver seen 

 any undulating or whip-like independent movement of the 

 pointed ends of 8. anodontae, no matter what means of obser- 

 vation I employed. Examination by means of a water-immer- 

 sion objective and ultra-microscopic condenser, fails to disclose 



