216 The Philippine Journal of Science 1919 
a bacteria eater. It must be remembered that we are dealing 
only with the forms seen by us. Chatterjee, in his original 
paper(3) describing Pentatrichomonas bengalensis, makes only 
incidental mention of the ingestion of blood corpuscles, and we 
do not know whether or not his species feeds on bacteria. 
Derrieu and Raynaud do not discuss the nutrition of the species 
seen by them. 
As a basis for future work looking to the clarification of the 
problem, it is suggested that Trichomonas and Tetratrichomonas 
might, for the present, be looked upon as feeding upon bacteria 
in the lumen of the bowel, and as occupying a position similar _ 
to that of Entameba coli; while the species of Pentatrichomonas 
cbserved by us, and also probably by Chatterjee, may be re- 
garded as a form subsisting on erythrocytes and possibly other 
tissue elements, and perhaps bearing the same relation to its 
host as does Entameba histolytica. That these differences may 
exist within the genus is, of course, to be taken into considera- 
tion; that is to say, certain species of Pentatrichomonas may, 
like their cousins Trichomonas and Tetratrichomonas, subsist on 
bacteria solely, while others derive their nourishment from tissue 
elements alone, or may even adopt either method of nutrition 
under certain physical and chemical conditions obtaining in the 
particular environment in which they happen to find themselves 
at the time, or at some definite period in the life cycle. These 
are things that are to be determined by future investigation. 
It is scarcely possible to go into the matter of tissue invasion 
on the basis of these observations, for that is purely conjectural. 
An autopsy on our case might or might not have developed 
interesting information on this point. Hadley, in his excellent 
studies on trichomoniasis in turkeys(7) has described in detail 
the mode of invasion of the intestinal wall through the goblet 
cells, and also the method by which the parasites later reénter 
the lumen of the intestine to complete their developmental cycle. 
We can, for the present, only surmise that such a thing might 
happen in man; but only histological study of the tissues in a 
case similar to ours can clear up that point. From his papers 
and from the study of preparations kindly sent to the senior 
author, we believe that Hadley has built up a strong case for 
Trichomonas in the intestine of the turkey. So far, the oppor- 
tunity has been lacking to make the study of the liver sections 
sent by Doctor Hadley that they deserve, but we regard his 
work as forming a good basis of attack on the problem in man 
when favorable material becomes available. The fact that the 
