154 



THE AMOEBAE 



ENDOLIMAX CAVIAE 

 HEGNER, 1926 



This species occurs commonly in the 

 cecum of the guinea pig. Hegner (1926) 

 found it in Baltimore and Hegner and Chu 

 (1930) found it in the Philippines. Nie 

 (1950) found it in 18% of 84 guinea pigs in 

 Pennsylvania. It is somewhat smaller 

 than E. nana, the trophozoites measuring 

 5 to 11 by 5 to 8n , but otherwise resem- 

 bles it. Nie saw one specimen with an 

 ingestion tube. The cysts are apparently 

 unknown. 



ENDOLIMAX GREGARINIFORMIS 

 (TYZZER, 1920) 

 HEGNER, 1929 



Synonyms: Pygolimax gregarini- 

 formis, Endolimax janisae, EndoUtnax 

 niimidae. 



large number of chickens he examined in 

 Pennsylvania. 



The trophozoites of E. gregariniformis 

 are usually 4 to 13 /i long with a mean of 

 9 by 5^1 , altho Hegner (1929a) found a 

 small race in the guinea fowl. The tropho- 

 zoites are oval, often with a posterior pro- 

 tuberance, and move sluggishly. The ecto- 

 plasm is not clearly separated from the 

 endoplasm. The food vacuoles contain bac- 

 teria. The nucleus is very similar to that 

 of E. nana but tends to have a larger endo- 

 some and a more apparent nuclear mem- 

 brane, often with chromatin granules at 

 the juncture of the achromatic threads with 

 the membrane. The cysts have 4 nuclei 

 when mature; they measure 7 to 8 by 8 to 

 11 /x with a mean of 10 by 7;i (McDowell, 

 1953). They tend to be somewhat lima 

 bean- shaped instead of truly ovoid, and 

 are often highly vacuolated. 



This species is found in the ceca of 

 the chicken, turkey, guinea fowl, pheas- 

 ant, domestic goose, domestic duck and 

 various wild birds, including the black 

 duck (Anas riibripes Iristis), black- 

 crowned night heron (Nycticorax nycti- 

 corax) and screech owl. 



E. gregariniformis was first des- 

 cribed by Tyzzer (1920) from the turkey; 

 he transmitted it easily to the chicken. 

 Hegner (1926) described it from the 

 chicken, naming it E. janisae. Hegner 

 (1929a) found the same species and an- 

 other form which he named E. numidae 

 in the guinea fowl. The latter was 

 smaller than E. gregariniformis , aver- 

 aging 4 by 3/i, but nevertheless fell within 

 its size range and did not differ from it 

 morphologically. Hegner (1929a) infected 

 chicks with both sizes of Endolimax irom 

 the guinea fowl and also with Endolimax 

 from the domestic goose, domestic duck 

 and screech owl. Richardson (1934) in- 

 fected chicks with Endolimax from the 

 duck, goose, pheasant, black duck and 

 black-crowned night heron. 



E. gregariniformis occurs thruout 

 the world and is non-pathogenic. 

 McDowell (1953) found it in over 50% of a 



Genus DIENTAMOEBA Jepps and 

 Dobell, 1918 



These are small amoebae, usually 

 with 2 nuclei. The nuclei are vesicular, 

 with a delicate membrane and an endosome 

 consisting of several chromatin granules 

 connected to the nuclear membrane by 

 delicate strands. No cysts are known. 

 Dobell (1940) considered that this genus 

 might be an aberrant flagellate closely 

 related to Histomonas . 



DIENTAMOEBA FRAGILIS 

 JEPPS AND DOBELL, 1918 



This species occurs in the cecum and 

 colon of man and also of some monkeys. 

 According to Belding (1952), it was found 

 in 4. 2% of 7120 persons in 14 surveys 

 thruout the world. Hegner and Chu (1930) 

 found D. frag His in 2 out of 44 Macaca 

 philippinensis in the Philippines, and 

 Knowles and Das Gupta (1936) found it in 

 1 out of 4 M. iriis in India. In addition. 

 Noble and Noble (1952) mentioned finding 

 a Dientamoeba in sheep feces in California. 



Only trophozoites are known for this 

 species. They are very sensitive to 



