xiv,2 Haughwout and de Leon: Erythrocyte Ingestion 213 
testinal Protozoa(8) and, although certain of the views therein 
expressed by the author have been modified by him in the light 
of more recent publications—particularly those of Wenyon and 
O’Connor and other British protozodlogists—it seems apropos 
to quote the following paragraph from the paper (p. 255): 
Next in order appears to be the desirability of attempting to explain 
the conflicting opinions expressed by different authors regarding the 
pathogenicity of the intestinal flagellates. It has been shown that some 
workers regard these forms as harmless or capable, at the most, of giving 
rise to nothing worse than diarrhcea, while others frankly express the belief 
that they may produce dysentery—actual lesions of the bowel. Is it pos- 
sible that we have here different strains of the same organism, some 
showing and others not showing tissue-invasive powers—a condition some- 
what resembling the relation between Entameba histolytica and Enta- 
meba coli? 
At least one other observer, Barlow,(1) has suggested that 
it “is not impossible” that there may be different strains, or 
even species, of Trichomonas and that some of them may at 
times be more or less pathogenic. 
In connection with this particular case, these facts must be 
carried in mind in the attempt to interpret our observation : 
(1) The patient, according to the assertion of her relatives, had 
suffered from an attack of dysentery of short duration some 
three years previous to this attack. (2) On admission to the 
hospital she showed characteristic clinical symptoms of dysen- 
tery, the stools passed were of dysenteric character, not merely 
diarrhceal, and contained large numbers of Pentatrichomonas. 
(3) Careful search by three observers failed to detect the pre- 
sence of Entamebda histolytica; the findings of three microsco- 
pists agreed in all other essential details. (4) The microscopic 
picture of the stool, though it was similar to that presented by 
many cases of flagellate infection we have seen, yet suggested 
the possibility of bacillary dysentery. 
The fact that the bacteriological examination for Bacillus 
dysenteriz was negative carries no weight with us, for our 
experience is that negative findings in such cases are worthless, 
especially if the stool has not reached the bacteriologist imme- 
diately after its passage.. So, in short, we are left in doubt as 
to whether the dysenteric symptoms were due to a protozoal, a 
bacterial, or a mixed infection. This is aside from the state- 
ment of Chatterjee that he recognizes flagellate dysentery as 
a distinct entity and incriminates Pentatrichomonas as one 
genus that may be an etiologic factor. 
To our minds the most important feature lies in the observa- 
