PROTOZOA 



411 



place with considerable rapidity, the two halves of the spiro- 

 chaete uncoil from each other (f, g) and separate at the point 

 of flexion (g), thus producing two parasites. Sometimes the 

 spirochaete breaks in two, before the daughter parasites have 

 uncoiled from each other (e) . In the former case the parasites 

 may remain connected together for some time before finally 



Fig. 94. Various stages in the flexions and transverse divisions of 

 Treponema (Spirochaeta) gallinarum. (After Hindle). 



separating (h) and in this case exactly resemble the forms of 

 transverse division previously recorded for these parasites. 



"Commencing with the ordinary parasite in the blood of 

 the fowl, the spirochaete grows until it reaches a certain length 

 (16 /u,-19 /A) and then divides by the peculiar mode of trans- 

 verse division described above. This process is repeated and is 

 probably the only method of multiplication 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 by Argas persicus, some of them pass 

 through the gut wall into the coelomic fluid. From this me- 

 dium they bore their way into the cells of the various organs 



