OF THE ALIMENTARY TRACT 97 



which as yet has not been well accepted by protozoolo- 

 gists and which must be held sub judice. These in- 

 vestigators use the phenomenon of phagocyting red 

 blood corpuscles as one of the main features of differ- 

 entiating the active forms of Endamoeha coli and 

 their Councihnania lafleuri. The particular features 

 of difference between the two as specified by them are 

 the "dispersed" karyosome of Councihnania as con- 

 trasted to the compact form of that of E. coli, and the 

 reproduction by budding from the cyst of the former. 

 The dispersed karyosome was present in some of the 

 cysts of the amoeba encountered in this experiment 

 but the process of budding was not seen at any time. 

 Should Kofoid's contention be accepted this experi- 

 ment will no doubt be considered to affect Council- 

 mania lafleuri and not Endamoeha coli. 



Dobell and O'Connor (1921) say of Endamoeha 

 coli, that the food "vacuoles never contain red blood 

 corpuscles," while Wenyon and O'Connor (1919) 

 state, "If amoebae containing red blood corpuscles are 

 present in the stool — they are Eiidamoeha histo- 

 lytica." This long accepted feature of difference be- 

 tween E. coli and E. histolytica must be held subject 

 to question as a positive means of differentiation for 

 the present. 



When the amoeba is obtained from the lower colon 

 or in the ordinary stool it is proceeding to encystment 

 or is already encysted. The "precystic" form is 

 smaller, it has stopped feeding, it is sluggish or mo- 

 tionless. If it shows pseudopodia they are small, its 



