AMCEBJE OF THE INTESTINAL TRACT. 207 



tetragena and the fact that the latter species also 

 occurs in South America throws some doubt upon 

 the validity of the species described by this author. 

 The one point of distinction appears to be the uni- 

 formly minute size of Entamceba minuta and if 

 further observation confirms the statements of 

 Elmassian in this respect it may possibly be accepted 

 as a new species, but it should be remembered that 

 mere difference in size must always be a doubtful 

 feature upon which to base a specific distinction. 



ENTAMCEBA NIPPONICA. Koidzumi, 1909. 



This species of amoeba was described in 1909 by 

 Koidzumi. He observed it first in an advanced case 

 of dysentery in a Japanese in conjunction with Enta- 

 moeba histotytica, but later he found it present in 

 mild cases of the amoebic type of dysentery, and in 

 some cases of bacillary dysentery. He also states 

 that it is not infrequently observed in patients suffer- 

 ing from diarrhoea. 



GEOGRAPHICAL DISTRIBUTION. The geographical 

 distribution of Entamceba nipponica is confined to 

 Japan so far as is at present known, but if this be 

 a distinct species it is probable that it will be found 

 widely distributed in the Far East. 



MORPHOLOGY. In the vegetative stage of devel- 

 opment this amoeba possesses the general features of 

 the Umax group, but the pseudopodia are never 



