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A REVISION OF THE COCCIDIA PARASITIC IN MAN. 
By CLIFFORD DOBELL, F.R.S. 
(Imperial College of Science.) 
(With Plate VIII and 2 Text-figures.) 
CONTENTS. 
PAGE 
Introduction.147 
Part I. Historic and Analytic . . . . . . . . 149 
A. The human cases of coccidiosis described prior to the year 
1915.150 
B. Opinions concerning the coccidial parasites of man, as 
expressed by the chief compilers and commentators . 164 
C. The coccidia described from man in 1915 and later . . 174 
D. Discussion and Conclusions.175 
Part II. Systematic and Descriptive.179 
The genera Eimeria and Isospora . . . . . . 180 
1. Isospora hominis Rivolta, 1878 (emend.) .... 182 
2. Eimeria wenyoni n.sp. . . . . . . . 187 
3. Eimeria oxyspora n.sp. ....... 188 
4. Eimeria (?) sp., the hepatic coccidium of man . . . 190 
Summary and General Conclusions . . . . . . . 193 
Bibliography.194 
Description of Plate .......... 197 
INTRODUCTION. 
The following memoir has grown gradually from very small beginnings until 
it has now assumed almost monographic proportions. Its history is as follows. 
Last year I accidentally discovered the oocyst of a coccidium in human faeces, 
and my attempts to identify it led me to study afresh the works of others 
dealing with the intestinal coccidia of man. From this I was led, little by 
little, to inquire into all the recorded cases of human coccidiosis which I could 
find. I had already studied this subject in some detail in the course of earlier 
work, and had perceived that our knowledge of the coccidial parasites of man 
was in a highly unsatisfactory condition; but I hardly realized, and I think 
few others even now fully realize, the state of decay into which it had fallen. 
Until the appearance of Wenyon’s papers in 1915 hardly any facts had been 
definitely established concerning the coccidia of man; and the interpretations 
put upon such observations as had been recorded were—as can now, I think, 
be shown—for the most part wrong. But the new facts discovered by Wenyon 
have now made it possible to revise and correct our knowledge of the whole 
group of human parasites, and to place the organisms themselves on a secure 
