392 
THE SPIROCHAETES FOUND IN THE CRYSTALLINE STYLE 
OF TAPES AUREUS: A STUDY IN MORPHOLOGICAL 
VARIATION. 
By H. B. FANTHAM, D.Sc. Bond. 
Christ's College, Cambridge, Assistant to the Quick Professor of 
Biology in the University. 
(With Plate VI and 2 Text-figures.) 
CONTENTS. 
PAGE 
Introduction. 392 
Technique ..393 
Observations on the Living Spirochaetes of Tapes aureus . . . 394 
General Morphology.395 
The various Spirochaetes of Tapes aureus ...... 396 
Division ............ 399 
Explanations of the Morphological Variation of Spirochaetes . . 400 
Possible infection of Tapes aureus with S. balbianii directly from 
the Oyster ........... 402 
Conclusions ........... 403 
References ............ 404 
Explanation of Plate.406 
Introduction. 
One of the earliest known Spirochaetes from Lamellibranchs was 
that briefly described by Certes in 1882 from the crystalline style of 
the oyster. Certes named the parasite Trypanosoma balbianii. In 
1891 the same worker recorded the occurrence of the organism in two 
species of Tapes, namely T. decussatus and T. pidlaster. Laveran and 
Mesnil in 1901 showed that Tr. balbianii probably belonged to the 
Spirochaetes. The organism is now known as Spirochaeta balbianii. 
