246 
Intestinal Protozoa of Man 
types of nucleus were seen, in the sluggish, or non-motile amoebae. In speci¬ 
mens stained by the Heidenhain haematoxylin method from all classes of 
cases the atypical forms of nucleus predominated, the E. histolytica type of 
nucleus being very rarely found. 
I am inclined to believe that the so-called “tetragena " nucleus of the free 
forms is due to a degenerative change caused by a contraction of the nucleus 
and a running together of the chromatin dots into clumps. The change can 
apparently take place very suddenly, since it was found in specimens fixed 
by the rapid wet-fixation method of corrosive sublimate and alcohol in cases 
which were on examination of fresh specimens obviously E. histolytica. 
The so-called “minuta" forms have frequently been seen containing two 
nuclei and several were observed in my series, but I have seen for the first 
time in Case W., who was suffering from acute amoebic dysentery, considerable 
numbers of amoebae containing red blood cells and at the same time possessing 
two nuclei. 
Throughout all the examinations only one case of simultaneous double acute 
amoebic and bacillary dysentery was observed: this was in the Case D. referred 
to in which Bacillus dysenteriae of Shiga was isolated. The bacilli of dysentery 
were found three times in cases harbouring Entamoeba histolytica cysts. B. 
shiga twice, and B. flexner Y once, but in these cases the protozoon appeared 
to have no effect on the patient’s condition at the time. 
It may be stated here that free and encysted intestinal protozoa were 
frequently found in the stools from which pathogenic bacteria were isolated. 
The presence of the latter appears to exercise no influence on the intestinal 
protozoa. 
Entamoeba coli. 
This parasite was found most frequently amongst Indian troops, and then, 
in order, in healthy Egyptians, sick Egyptians, and white troops. I observed 
no evidence of the pathogenicity of this parasite in the 923 cases in which I 
encountered it. It was demonstrated by Wenyon and myself in 1916 that 
when faeces containing Entamoeba coli were mixed with fresh blood and kept 
warm in the laboratory, the blood cells tended to run together around the 
amoeba and adhere to it, but that in no case were they seen inside the parasite: 
further it was noticed that the amoeba did not try to ingest the cells. During 
my examination of the above cases, including a number of Schistosoma 
infections where the patients were passing almost pure blood in which 
Entamoeba coli were found, I have observed the same phenomenon. 
The Inclusions of Entamoeba coli. 
Foreign bodies of various kinds, including protozoa, have been reported 
by many observers as being found in free E. coli. In my examinations the 
following inclusions were found: 
