THE AMOEBAE 



145 



range in diameter from 7 to 21 ji with 

 means of 10 to 15ju in different rabbits. 



ENTAMOEBA GALLINARUM 

 TYZZER, 1920 



This non-pathogenic species was des- 

 cribed from the ceca of the chicken and 

 turkey by Tyzzer (1920). By cecal inocu- 

 lation of parasite-free baby chicks, 

 Richardson (1934) found what appeared to 

 be the same species in the ceca of the 

 domestic duck, turkey and goose. E. 

 galliiiaruni is common. McDowell (1953) 

 found it in about 30% of a large number of 

 chickens he examined in Pennsylvania. 



E. gallinarmu closely resembles E. 

 coli. The trophozoites are 9 to 25jj, in 

 diameter, most measuring 16 to 18|i. 

 The endoplasm is highly vacuolated and 

 contains many food vacuoles. Altho 

 Tyzzer (1920) said that E. galliiiaruni 

 did not ingest bacteria, McDowell (1953) 

 found that bacteria were its main food, 

 altho it also ingested Trichouionas among 

 other foods. The ectoplasm is clear or 

 granular. The nucleus is 3 to 5 ji in di- 

 ameter, with an eccentric endosome and 

 a row of granules around the outside. 

 The mature cysts are 12 to 15/i in diam- 

 eter and contain 8 nuclei. 



found it in the feces of 4 gnus ( Conno- 

 chaetes taurinus) in the London zoo. It 

 has been described most recently by Noble 

 (1950) and Noble and Noble (1952). The 

 trophozoites are 5 to 20jj. in diameter. 

 The cytoplasm is smoothly granular and 

 filled with vacuoles of various sizes. The 

 nucleus is large, with a large, central 

 endosome made up of compact granules 

 and a conspicuous row of chromatin gran- 

 ules of different sizes around its periphery. 

 The cysts are 4 to 14 p. in diameter and 

 contain a single nucleus when mature. 

 Their chromatoid bodies are irregular 

 clumps of varying size and rods, splinters 

 or granules. A large glycogen vacuole 

 may or may not be present. 



Noble and Noble (1952) found that the 

 uninucleate entamoebae from the feces of 

 cattle, goats, sheep and swine were mor- 

 phologically indistinguishable. However, 

 since their physiological characteristics 

 have not been studied and cross infections 

 have not been attempted, they considered 

 it best not to assign them all to the same 

 species. If future work should show that 

 they are all the same, their correct name 

 would be E. bovis. 



ENTAMOEBA OVIS 

 SWELLENGREBEL, 1914 



Richardson (1934) transferred infec- 

 tion from chick to chick by association in 

 the same cage. She found that the mini- 

 mum oral infective dose of E. gallinarum 

 for the chick was 240 cysts, and observed 

 that the cysts remained viable in raw 

 feces for 10 days and in feces diluted with 

 water for at least 28 days. 



ENTAMOEBA BOVIS 

 (LIEBETANZ, 1905) 



Synonym : Amoeba bovis. 



This non- pathogenic species occurs 

 commonly in the rumen and feces of cattle 

 thruout the world. Noble and Noble (1952) 

 found it in the feces of all of 34 cattle 

 from California, Pennsylvania, Korea 

 and Japan. Mackinnon and Dibb (1938) 



Synonym: Entamoeba debliecki, pro 

 parte". 



This non- pathogenic species was first 

 described from the intestines of sheep in 

 Sumatra, but it is common thruout the 

 world. Noble and Noble (1952) found it in 

 the feces of all of 25 sheep from California 

 and Washington. Triffitt (1926) reported 

 it from the feces of the sable antelope 

 {Hippotragiis niger) and common water- 

 buck ( Cobus ellipsiprymus) in Africa. 



By a historical accident, the name of 

 the pig entamoeba rather than that of the 

 sheep entamoeba has been used for the 

 entamoeba of the goat. Nieschulz (1923) 

 gave the first description of E. debliecki 

 (a synonym of E. snis) from the pig and 

 soon after (1923a) found what appeared to 

 be the same species in the large intestine 



