2 annip: porter 



theless, the life-liistory of ail Spirochaetes seems to take much 

 the same course, their movements are similar, and their mode 

 of multiplication witliin the host develops along similar lines. 

 Two of the largest Spirochaetes known are Spirochaeta 

 halhianii and 8. anodontae, from Lamellibranchs, and by 

 observations of thèse two organisms valuable information as 

 to the movements and morphology of smaller Spirochaetes 

 can be obtained. A long paper by D^' H. B. Fantham appeared 

 in the (( Quarterly Journal of Microscopical Science » for Jan- 

 uary 1908, and the morphology and movements of thèse orga- 

 nisms were very fully and thorouglily described, and little 

 that is really new or of fundamental importance regarding 

 thèse organisms lias been published since. 



II. — Material and Methods. 



Some of the Oysters, for the study of *S^. halhianii, were 

 obtained in London. Infected French Oysters were also exa- 

 mined at the Laboratoire Arago, Banyuls-sur-Mer, and were 

 taken fresh from the sea. Crystalline styles were rarely pré- 

 sent in the Oysters, but Spirochaetes were found swimming 

 freely in the gut-contents. I hâve much pleasure in thanking 

 Prof essor s Pruvot and Racovitza for their kindness to me 

 while at Banyuls. 



Most of the infected Anodons used {Anodonta cygnea) 

 were obtained through the kindness of Professor Nuttall of 

 Cambridge, from a local stream, though some were procured 

 in the neighbourhood of London. Spirochaetes were présent 

 in nearly ail the Anodons examined, and the infection was 

 frequently heavy. Crystalline styles were usually présent in 

 the Anodons examined. 



Spécimens of Mytilus edulis, obtained from the southern and 

 eastern coasts of England, were also examined for Spirochaetes. 

 Large numbers of Mytilus were dissected at various times, and 



