476 
Spirocliaeta gallmarum 
Summary. 
The life-cycle of S. galli'imrum may be briefly summarised as 
follows: 
Commencing with the ordinary parasite in the blood of the fowl, the 
spirochaete grows until it reaches a certain length (16 /r-19 g) and then 
divides by the peculiar mode of transverse division described above. 
This process is repeated and is probably the only method of multiplica¬ 
tion of the parasite within the blood. When the spirochaetes disappear 
from the circulation some of them break up into coccoid bodies which, 
however, do not usually redevelop in the fowl. When the spirochaetes 
are ingested hy Argas persicus, some of them pass through the gut wall 
into the coelomic fluid. From this medium they bore their way into 
the cells of the various organs of the tick and there break up into a 
number of coccoid bodies. These intracellular forms multiply by 
ordinary fission in the cells of the Malpighian tubules and gonads. 
Some of the coccoid bodies are formed in the lumen of the gut and 
Malpighian tubules. The result is that some of the coccoid bodies may 
be present in the Malpighian secretion and excrement of an infected 
tick and when mixed with the coxal fluid may gain entry into another 
fowl by the open wound caused by the tick’s bite. They then elongate 
and redevelop into ordinary spirochaetes in the blood of the fowl, and 
the cycle may be repeated. 
REFERENCES. 
Acton, H. W., and Harvey, W. F. (1911). The Nature and Specificity of Negri 
Bodies. Parasitology, iv. 255-272. 
Balfour, A. (1908). Spirochaetosis of Sudanese Fowls. Third Report Wellcome 
Research Laboratories, 38-58. 
- (1911). The role of the infective granule in certain Protozoal infections as 
illustrated by the Spirochaetosis of Sudanese Fowls. Journ. Trop. Med. and 
Hyg., XIV. 113-114. 
Blanc, G. R. (1911). Les Spirochetes. These de la Faculte de Medecine. Paris, 
Jouve & C‘®. 
Bosanqdet, W. C. (1911). Brief notes on the Structure and Development of 
Spirochaeta anodontae Keysellitz. Quart. Journ. Micr. Sci., LVi. 387-393. 
Dobell, C. C. (1911). On Cristispira veneris nov. spec., and the Aftinities and 
Classification of Spirochaets. Quart. Journ. Micr. Sci., lvi. 507-541. 
Fantham, H. B. and Porter, A. (1909). The mode of division of Spirochaeta 
recurrentis and S. duttoni, as observed in the living organism. Proc. Roy. Soc. 
Lxxxi. B., 500-505. 
