F. W. O’Connor 
247 
Entamoeba histolytica cysts... ... ... ... Twice 
Lamblia cysts ... ... ... ... ... Twice 
Free Lamblia , non-motile and apparently dead ... Once 
Chilomastix cysts ... ... ... ... ... Once 
Vegetable cells resembling Chilomastix cysts ... Once 
Isospora hominis oocysts ... ... ... ... Once 
In one of the cases of Lamblia inclusions, no less than 30 different 
amoebae were found to have taken up one or more cysts: in many of these 
two cysts were included, in a few three, and in one degenerated parasite, in 
which, however, the outlines of cell and nucleus could still be made out, there 
were five. In stained specimens from this case I have found many amoebae 
with two Lamblia cysts included. In the fresh state, amoebae, containing 
many cysts, were motile and apparently healthy. In several instances, how¬ 
ever, although the cell was motile, the nucleus was large and faint with small 
masses of chromatin distributed round the edge and throughout its interior. 
The case of Isospora inclusions was especially interesting. Captain 
McLean, R.A.M.C., sent me the specimen as a case of Coccidiosis for confirma¬ 
tion of his diagnosis. The oocysts developed in three days to the state typical 
of Isospora, viz., two sporocysts, each containing four sporozoites and residual 
body. As the infection was a heavy one, I asked Captain McLean to send me 
specimens daily in order that I might follow the case. This he very kindly 
arranged to do. The patient also had a large infection of Entamoeba coli. On 
the third examination I discovered an oocyst rolling on the slide like a Rugby 
football on its long axis, and on closer examination I observed a motile 
amoeba stretched over it, the nucleus of the amoeba being quite clear and 
typically E. coli in appearance; the rolling over movement of the oocyst was 
obviously due to the movements of the investing amoeba, and the latter was 
apparently unaffected by the enormous inclusion. On further examination 
I found more than ten amoebae with similar inclusions. I made several 
Heidenhain haematoxylin preparations and I was fortunate in getting some 
well stained specimens in which, although the contents of the oocysts cannot 
be made out, yet the walls and contour of the Isospora are clearly demonstrable 
within the amoeba. 
When free protozoa are ingested by free Entamoeba coli it seems reasonable 
to assume that the former may be digested. In the case of the free Lamblia 
which I found in one E. coli the flagellate was non-motile and granular. But 
in the case of inclusion of the highly resistant protozoal cysts the effect on 
the amoeba or on its inclusion is not so easily explained. As I have already 
stated, I have seen Isospora oocysts and Lamblia cysts in actively motile 
E. coli which were apparently in no way affected by such inclusions. In one 
Lamblia case the nuclei of the investing amoebae had undergone change in 
spite of non-interference with the motility of the parasite: the nuclei in these 
amoebae were enlarged, spherical, and faintly outlined; the blocks of chromatin 
