104 



THE TRICHOMONADS 



measuring 3 to 7 by 5 to 8 |i with a mean 

 of 5 by 7 ji. The undulating membrane ex- 

 tends the full length of the body, with a 

 free flagellum at its end. A costa is pres- 

 ent (Allen, 1940 called it a parabasal body). 

 A row of paracostal granules runs between 

 the costa and the undulating membrane. 

 The axostyle is slender, projecting from 

 the posterior end, but not discernible in 

 rounded-up specimens. A cytostome is 

 present. The blepharoplast is composed 

 of a group of small granules. 



Pathogenesis : As mentioned in the 

 discussion of Trichomonas galli)iaru))i , 

 Allen and others isolated this form from 

 turkey liver lesions resembling those of 

 histomonosis and attributed the disease to 

 it. However, post hoc reasoning is not 

 enough, and there is as yet no acceptable 

 proof that this trichomonad is pathogenic. 



Remarks : Allen (1936) first assigned 

 this species to the genus Pentatrichomonas 

 without naming it. She later (1940) des- 

 cribed it as a five-flagellate "Trichom- 

 onas galli>iarum Martin and Robertson, 

 1911". Later authors such as Morgan and 

 Hawkins (1952) called it Pentatrichomonas 

 gallinaritm. The species described by 

 Martin and Robertson has 4 anterior fla- 

 gella, as does the form described by 

 McDowell (1953). Further study is needed 

 to determine the relationship between the 

 two forms. 



Genus DfTR/CHOMONAS 

 Cutler, 1919 



Similar to Trichomonas, but with 2 

 anterior flagella. 



DITRICIiOMONAS OVIS 

 ROBERTSON, 1932 



Host : Sheep. 



Location : "Gut. " 



Geographic Distribution : England. 



Prevalence : Robertson (1932) found 

 this species in 1 out of 86 sheep in a Lon- 

 don abattoir. 



Morphology : The protozoa were des- 

 cribed from cultures. The body is slightly 

 ovoid or nearly spherical, 3 to 14 by 3 to 

 10 ji, with 2 anterior flagella, one 12 to 

 16. 5/i and the other 7. 5 to 10. 5^ long. 

 The undulating membrane is poorly devel- 

 oped but extends the whole length of the 

 body. A free flagellum was described as 

 present, but was absent in 7 out of 9 draw- 

 ings. A costa is present. The axostyle 

 extends beyond the body. Three blepharo- 

 plasts and another granule described as a 

 parabasal body are present. 



Pathogenesis : Non- pathogenic. 



Cultivation : Robertson (1932) culti- 

 vated D. ovis in Tanabe's medium with or 

 without added rice starch. 



Remarks: Robertson's paper was 

 apparently overlooked by Grasse, Reich- 

 enow and others who discussed the validity 

 of the genus Ditricho)nonas. Robertson 

 insisted that there are only 2 anterior fla- 

 gella except when the protozoa are divid- 

 ing. No one else appears to have studied 

 the intestinal trichomonads of sheep care- 

 fully, altho they are more common in the 

 United States than Robertson found them 

 to be in England. Whether they are the 

 same species remains to be determined. 



LITERATURE CITED 



Allen, EnaA. 1936. Trans. Am. Micr. Soc. 55:315-322. 

 Allen, EnaA. 1940. Proc. Helm. Soc. Wash. 7:65-68. 

 Allen, EnaA. 1941. Am. J. Vet. Res. 2:214-217. 

 Anderson, E. 1955. J. Protozool. 2:114-124. 

 Andrews, J. and C. Rees. 1936. J. Parasit. -22:108. 

 Bartlett, D. E. 1947. Am. ]. Vet. Res. 8:343-352. 

 Bartlett, D. E. 1948. Am. J. Vet. Res. 9:351-359. 

 Bartlett, D. E. 1949. ]. Am. Vet. Med. Assoc. 114:293-305. 

 Bartlett, D. E. and G. Dikmans. 1949. Am. J. Vet. Res. 



10:30-39. 

 Bartlett, D. E. , K. Moist and F. A. Spurrell. 1953. J.Am. 



Vet. Med. Assoc. 122:366-370. 

 Bos, A. 1934. Zbl. Bakt. I. Grig. 132:453-458. 

 Brodie, B. O. 1960. J. Am. Vet. Med. Assoc. 136:501-504. 

 Burch, T. A., C. W. Rees and L. V. Reardon. 1959. Am. 



J. Trop. Med. Hyg. 8:312-318. 

 Buttrey, B. W. 1956. J. Protozool. 3:8-13. 

 Callender, G. R. and J. S. Simmons. 1937. Am. J. Trop. 



Med. 17:579-585. 

 Christl, H. 1954. Ztschr. Parasitenk. 16:363-372. 

 Cleveland, L. R. 1928. Am. J. Hyg. 8:232-255. 

 Delappe, I. P. 1957. Exp. Parasit. 6:412-417. 

 Diamond, L. S. 1954. Exp. Parasit. 3:251-258. 



