427 
ON THE CYSTS OF A HITHERTO UNDESCRIBED 
SPECIES OF EIMERIA IN HUMAN STOOLS. 
By E. P. SNIJDERS. 
(From- the Pathological Laboratory , Medan, East Coast of Sumatra.) 
(With 1 Text-figure.) 
I. 
Mr C., who has lived for ten years in the tropics, was under the care of 
Dr de Jong and myself for chronic amoebic dysentery. Some five years ago 
he suffered from an abscess of the liver, readily cured after operation. Before 
this abscess he had never noticed any dysenteric symptoms, but afterwards 
he often had mild, or sometimes more severe, attacks of recurring dysentery, 
most times without fever. During the attacks, the bloody slime contained a 
great number of amoebae, principally of Entamoeba histolytica and containing 
erythrocytes. With an “emetine cure” the attacks regularly subsided; but 
between two attacks the patient produced constantly a great quantity of 
so-called “minuta forms” and 4-nucleate (“ tetragena”) cysts of this species 
in the faeculent parts of the stools. After an emetine treatment I often found 
a rather sudden increase in the number of cysts (always measuring from 
11-5-13*5/x), sometimes to a tremendous amount 1 . Several times we tried to 
get rid of the amoebae by a cure with emetine bismuthous iodide, but without 
success, so the patient stayed under observation and regularly sent us his 
stools for control. 
Now in the beginning of April, 1920, I received his stool once more, half- 
an-hour after he had passed it into a clean Petri dish. (This is our routine 
method to prevent contamination.) The stool was faeculent and pultaceous 
and contained no mucus or blood. 
I found a few “minuta forms,” but to my astonishment many round cysts, 
occurring uniformly in all parts of the faeces, but of larger dimensions than any 
that I had ever seen in human stools. 
. Without difficulty one could see that most of these cysts contained four 
whetstone-shaped structures strongly suggesting spores. These spores, in their 
turn, each enclosed two bodies—probably sporozoites; so on the whole I felt 
sure that I had the oocysts of some species of Eimeria before me. Some of 
the oocysts, however, were not completely differentiated; very few of them 
contained only one undifferentiated sphere showing a honeycomb structure, 
some others only two spores. 
1 Indeed for some time he formed my regular supply of cysts. 
Parasitology xii 
28 
