494 Mr. II. B. Fantham on Spirochgeta "^ 



Historical. 



Spirochceta [Trypanosoma) Balbia7iii was first recorded by 

 Certes from French oysters in 1882 [i], though Mobius, 

 writing in 1883 [7], stated that he observed the parasite in 

 1869 in oysters from Schleswig-Holstein. It was found in 

 the crystalline style and intestine of the host. Lustrac [6], 

 in 1896, gave particulars of longitudinal division. In 1901 

 the famous protistologists Laveran and Mesnil [5] briefly 

 described the main features of the organism, and stated that 

 it was really a Bacterium allied to tlie Spirilla and Spiro- 

 cha^tes. In 1905-06 Perrin [8, 9] described the life-history 

 of the organism, but still retained it in the genus Trypano- 

 soma, although it lacks a flagellum, Certes having placed it 

 in tliis genus years before because it possessed an undulating 

 membrane ; but at that period the genus Trypanosoma was 

 ill-defined. Short notes have since appeared by Swellen- 

 gvebel [10], Vl6s [n], and Fantham [3]. 



Spirochata anodontce was recorded from the crystalline 

 style of Anodonta mutabilis (which is not a British species) 

 by Keysselitz in 1906. It has not before been noted in 

 A. cygnea, so far as I am aware. 



Material and Methods. 



Spirochceta Balhianii has been studied by me in oysters at 

 Roscoff last summer, and in this connexion I would especially 

 thank Professor Delage and M. Fred Vl^s. The further 

 studies on this organism were continued in London, on more 

 living material, though infected oysters were only procured 

 with much difficulty. 



As regards Spirocha^ta anodontce from the crystalline style 

 of Anodonta cygnea^ after repeated attempts, during which 

 only a few parasites were found, I obtained an infected strain 

 in Anodons from Godalming, very kindly supplied to me by 

 Mr. O. H. Latter, to whom my best thanks are tendered. 



I have spent much time examining both these Spirochsetes 

 in the living condition, in their natural medium as far as 

 possible. I am convinced that too much stress cannot be 

 laid on the necessity for this careful examination of living 

 material ; it is not sufficient to rely on stained preparations 

 alone. 



As regards fixed and stained material, best results were 

 obtained from thin smears of gut-contents or solutions of the 

 crystalline style (in a little sea- water in the case of Ostrea, 

 in fresh water in the case of Anodon), the preparations being 



