24 AKNIE PORTER 



been noticed to simiilate cysts, siich as tliose described by 

 Perrin and others. 



130 Tlie spiral path of Spirochaetes is often revealed as a 

 clear helicoid area around them, which is formed by their 

 movements as they spirally bore their way, by the aid of their 

 membranes, through the somewhat viscid médium surroun- 

 ding them. 



140 -phe distribution of the Spirochaetes within LameUi- 

 branchs is largely confined to the crystalhne style and to the 

 sac in which this lies. The « flèche tricuspide » is very rarely 

 infected. Spirochaetes hâve been removed from the mouth and 

 mantle cavities of the moUuscs. 



150 The mode of cross-infection is a casual one, for Spiro- 

 chaetes hâve been found in the water in which the moUuscs 

 were kept, and in the fluid of their mantle cavities and 

 moutlis, as well as in their styles. Cross-infection occurs by 

 the mouth. 



16° Increase of température, e. g. to 20° C, causes the move- 

 ments of the Spirochaetes of Lamellibranchs to quicken. 

 Greater beat (e. g. 30» C) kills them. 



17° S. haïbianii and 8. anodoiitae move more slowly in hyper- 

 tonic média. Glycérine and vaseline slow their movements 

 slightly but otherwise appear to hâve little efïect upon them. 



18° Increased light causes coiled up forms to uncoil. 



190 There is no évidence of either sexuality or conjugation in 

 Spirochaetes. 



REFERENCES TO LITERATURE 



BoKKKb A. et Mlle Geenovodeanu (1907). — « Membrane ondulante du 

 Spirochaeta balbianii.)) G. R. Soc. Biol., LXII, p. 1102. 



BoBREL A. (1908). — « Spirilles, Spirochètes, Trypanosomes. » Bull. Soc. 

 Pathologie exotique, I, pp. 151-155. 



Dtttton J. e. and Todd, J. L. (1907). — « A Note on the Morpholof^y of 

 Spirochaeta duttoni. » Lancet, pp. 1523-1525, Nov. 30., 1907. 



