168 
Coccidia parasitic in man 
cat and dog also. If we seek his grounds for this belief, they are difficult to 
find. In fact his opinion appears to rest mainly upon a general belief that there 
are only a few species of coccidia. As evidence that the hepatic coccidia of 
man and rabbit are the same, he advances the argument that Gubler’s case 
probably acquired his infection from a rabbit; for the singular reason that he 
lived in France, and France is well known to be the home of rabbit-breeding 1 . 
It is to be noted that neither as regards Gubler’s case nor any of the other 
recorded cases of human hepatic coccidiosis, is there even the slightest evidence 
of the patient’s previous contact with rabbits. 
Evidence for his belief in the identity of the intestinal coccidia of man, the 
rabbit, the dog, and the cat, Leuckart has none, beyond the fact that all the 
parasites occupy a similar site in their hosts. 
It is only fair to acknowledge that Leuckart could hardly be expected to 
hold correct views concerning the Coccidia, since our knowledge of these 
organisms—and, in fact, of all the Sporozoa—was both deficient and inaccurate 
at the time when he wrote. Nevertheless, it is somewhat surprising that his 
baseless speculations should have been treated with the respect and approval 
which they have verv generallv received from later workers. 
Rivolta (1873), who had himself studied the coccidia of the rabbit, merely 
notes the occurrence of similar “psorosperms'’ in the cat and in man 2 3 . He 
does not express any opinions regarding them. After a further study of 
I sos for a bigemina* , however, he attempted a classification of all the coccidia 
known to him (Rivolta, 1878). He regarded the coccidia of man 4 as distinct 
from Eimeria stiedae and Isos for a bigemina, and named them Cytosfermium 
hominis. He placed I. bigemina in the same genus (“Cytosfermium”), but 
referred the rabbit coccidia to a different one (“ Psorosfermium"). Although 
no definitions of his genera are to be found either here or elsewhere in his 
works, his general conception of the relations of these forms to one another 
was thus, as far as it went, approximately correct. 
Biitschli (1882), in his great treatise on the Protozoa, deals with the early 
history of the investigation of the Coccidia. He refers to the human cases of 
infection then known, but does not attempt to identify or classify the parasites. 
Somewhat later, Balbiani (1884) traverses the same ground. He also alludes 
to the coccidia found in man, and says they are supposed to be the same as 
those of animals (rabbits, etc.); but of this he seems doubtful. 
Blanchard (1889) deals with the coccidia of man in some detail. He cites 
correctly the cases of hepatic infection recorded by Gubler and Leuckart, and 
regards the parasites present in all these as “ Coccidium oviforme ”— i.e. as 
1 “In Frankreich ist bekanntlich die Kaninchenzucht mehr als sonst irgendwo zu Hause” 
(Leuckart, 1879, p. 280). He then proceeds to draw a fanciful picture of how Gubler’s case, “with 
a certain probability,” acquired his infection—by drinking water from an imaginary cistern con¬ 
taminated by proximity to a hypothetic rabbit-hutch. 
2 He refers only to Gubler’s case ( vide Rivolta (1873), p. 382). 
3 See Rivolta (1877, 1877 a). 
4 The only cases which he mentions are those of Eimer (1870). 
