170 
Coccidia parasitic in man 
thus included among the coccidia. For reasons which are not given he now 
regards Virchow’s parasites (“pentastome eggs”) as “more or less related” to 
this form. 
Blanchard’s (1900) more recent account of the coccidia of man is essentially 
a repetition of that just summarized (Blanchard, 1896). 
In his two later works Blanchard makes no reference to his earlier doubts 
regarding the identity of the hepatic coccidia of man and rabbit. He appears 
to agree with Leuckart in regarding all the coccidia of man as identical with 
those found in other animals. The chief differences between his earlier and later 
works, and between his and Leuckart’s, are merely differences in nomenclature. 
I have considered these two authors at some length, for their opinions have 
influenced all later writers—most of whom appear, indeed, to have copied 
them without verification or criticism. 
L. Pfeiffer (1891), in his work on the parasitic Protozoa, mentions the 
Coccidia of man. The human cases of coccidiosis are, he says (p. 56), given in 
Leuckart’s works: but he records (p. 57) that the “cysts'" of the human 
parasite have a size (“Masse”) of “56mmm.,” citing as his authority one 
“Dechsler,” to whose work he gives no reference. The only explanation which 
I can suggest of this statement is that Pfeiffer confounded Dressier’s case 
(= “Dechsler’s”?), given in Leuckart, with the measurements of Virchow’s 
parasites, as estimated by Blanchard (1889). If we may judge from the rest 
of his book, a mistake of this sort might quite well have been made by this 
author. It may be added that he apparently regarded E. stiedae, E. perforans, 
and all the coccidia found in.man—both hepatic and intestinal—as belonging 
to one and the same species. 
In his well-known Treatise , Railliet (1895) gives an account of the 
coccidia of man essentially similar to that of Blanchard. He says Eimeria 
stiedae 1 “can invade the human liver, as the observations of Gubler, Dressier,. 
Peris and Sattler, von Sommering (Leuckart), Silcock, etc. 2 show " (p. 138). 
Eimeria perforans*, he says, develops in the intestinal epithelium of the rabbit 
and man (p. 138); and as human cases he gives Eimer’s. He says further that 
“various observers, among others Grassi, Rivolta, Railliet and Lucet,” found 
coccidia in human faeces. Their site of infection is unknown, and the species 
to which they belong therefore uncertain: but he considers that the patients 
studied by himself and Lucet 4 were probably infected with Isospora bigemina 5 
(p. 140), and that Kjellberg’s coccidia were also probably of this species 
(p. 146). Virchow’s own case, he says, is “quite clearly a coccidium,” and 
probably an Eimeria, as also is the organism described by Kunstler and Pitres 
(p. 133). As we have already noted, this is not at all obvious: in fact, I am 
1 “ Coccidium oviforme Leuckart — C. cuniculi Rivolta.” 
2 I do not know who these others are supposed to be, since Railliet appears to have named 
all the known cases already. 
3 “ Coccidium perforans Leuckart = C. hominis Rivolta.” 
4 Railliet and Lucet (1890). 
5 “Coccidium bigeminum Stiles.” 
