PARASITIC AMCEBJE OF MAN. 



no data concerning its relation to dysentery, beyond 

 its occurrence in a single case of this disease. At the 

 present writing his observations have not been con- 

 firmed. 



ENTAM(EBA UNDULANS. Castellani, 1905. 



Castellani describes an organism occurring in the 

 feces of patients in Ceylon, suffering from diarrhoea, 

 which he considers a new species of amoeba, and to 

 which he has given the name of Entamceba undulans. 

 The organism measures from 25 to 30 microns in 

 diameter, is oval or round in shape and, unlike other 

 amoebae, it possesses an undulating membrane which 

 is in constant motion. A long narrow pseudopodium 

 is rapidly extruded from the body of the parasite at 

 frequent intervals and is quickly withdrawn, and only 

 one pseudopodium is extruded at a time. The proto- 

 plasm is finely granular and there is no distinction 

 between the ecto- and endoplasm. The nucleus is 

 generally invisible and the endoplasm contains a 

 single small vacuole, varying in position. He was 

 unable to observe division and no encysted forms were 

 noticed. 



The close resemblance of this parasite to certain 

 stages in the life-cycle of Trichomonas intestinalis 

 suggests that the author may have been observing 

 forms of the latter organism, although he states that 



