236 Arthropods as Essential Hosts of Pathogenic Protozoa 



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 



Development 

 Coccoid 



tion by trans- 

 fers t 



formation of 

 Coccoid bod/ej 

 in blood 



Spirochseta gallinarum. After Hindle. 



then elongate and redevelop into ordinary spirochaetes in the blood 

 of the fowl, and the cycle may be repeated. 



Hindle's account is clear cut and circumstantial, and is quite in 

 line with the work of Balfour, and of Leishman. Radically different 

 is the interpretation of Marchoux and Couvy (1913). These investi- 

 gators maintain that the granules localized in the Malpighian tubules 

 in the larvae and, in the adult, also in the ovules and the genital ducts 

 of the male and female, are not derived from spirochaetes but that they 

 exist normally in many acariens. They interpret the supposed 



