PROTOZOA 413 



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 Mal- 

 pighian 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." 



TREPONEMA (SPIROCHAETA) THEILERI. 



Synonyms. Spirillum ovina; Spirillum Theileri; Spi- 

 rochaeta ovis; Spirochaeta equi. 



Place in nature. This organism was discovered by 

 Theiler a in 1902 in the blood of cattle and sheep. Theiler re- 

 ports the occurrence of spirochaetes in sheep in the Transvaal 

 which resemble very closely the one in question and it is pos- 

 sible they are identical. He also discovered spirochaetes asso- 

 ciated with a disease of horses in South Africa and later it was 

 reported from the west coast of South Africa. Novy and 

 Knapp have designated this latter one Spirochaeta equi. Todd 

 believes that spirochaetes from cattle and sheep belong to the 

 same species. 



Morphology. It resembles morphologically Treponema 

 anserina. It varies from 0.25 to 0.4 /x in width and from 10 to 

 30 p in length. 



SPIROCHAETA MICROGYRATA LOWENTHAL VARIETY GAYLORDI. 



Calkins 2 describes the spirochaeta of mouse cancer dis- 

 covered by Gaylord and which appears to be identical with the 

 Spirochaeta microgyrata of Lowenthal 3 found in ulcerated 

 human carcinoma, in a dog tumor and in feces. Calkins' de- 



1 Theiler. Jour. Comp. Path, and Therap., Vol. XVII (1904) p. 48. 



2 Calkins. Jour, of Inf. Diseases, Vol. IV (1907) p. 171. 



3 Lowenthal. Berlin, klin. Woch., Bd. XLIII (1906) p. 43. 



