154 
Coccidia parasitic in man 
It must be confessed that the description of this case is far from satisfactory, 
and the identification of the “ coccidia - ’ now quite impossible. 
Leuckart (1879, p. 282) gives yet a third case, “in which likewise our 
coccidia were demonstrable/’ which was also sent to him by Peris. It con¬ 
sisted of a preparation out of a collection made by von Sommerring and later 
incorporated in that of the Pathological Institute at Giessen. No description 
is given either of the case or of the parasites, but Leuckart says that the 
specimen was labelled “an Distomis orta .” He believed this to be a corrupt 
reading of “an Distomatis ova?." And it may be noted that at that date it was 
quite usual to regard the oocysts of coccidia as eggs of trematodes or other 
worms. Nevertheless, I cannot regard this case as anything but highly 
doubtful. Even if it be granted that the preparation contained coccidia, there 
is no proof that they were of human provenance. The origin of the preparation 
is unknown, its authenticity unvouched for, its label admittedly wrong. And 
it is far from improbable that the coccidia—if such they were—which it 
contained were those of the rabbit. For it is by no means unlikely that 
von Sommerring, when engaged in collecting materials for a study of ulcera¬ 
tion of the bile ducts, should have included in his collection specimens 
illustrating a condition so common in the rabbit and already well known at 
that date. 
The three cases just described constitute the whole of Leuckart’s contri¬ 
bution to the facts concerning human coccidiosis. Dressier's case, which he 
never saw, is, perhaps, the best attested. There is a very brief account of it, 
it was known to be a human case, and we have Dressler’s own drawings of his 
findings from which to form an estimate of his parasites. Sattler’s case, of 
which Leuckart saw a bad preparation and a drawing, and of which he learnt 
otherwise at third hand, is far more questionable. One may well hesitate to 
draw any definite conclusions from it. Finally, the case of Peris (von Sommer- 
ring’s preparation) has so little to support it, that, by itself, it is almost without 
value. If hepatic coccidiosis were a common condition in man, these last two 
cases might, perhaps, be less open to question. But when they constitute more 
than a third of the known, or alleged, cases on record, they require something 
more than Leuckart’s loose statements for their substantiation. 
Leuckart’s opinions concerning the cases which he recorded are well known, 
and will be considered again later. It will suffice to note here that he regarded, 
without any apparent justification, all the hepatic coccidia of man as identical 
with those which occur in the liver of the rabbit. 
Although it will be evident from wdiat has just been said, I would here 
emphasize the fact that the original cases of human coccidiosis recorded by 
Leuckart are only three in number. Later authors have, apparently, been 
misled into supposing that there v r ere four or even five 1 . I would also note 
1 The five cases sometimes given are those of (1) Dressier, (2) Peris, (3) Sattler, (4) von 
Sommerring, (5) Leuckart. From the foregoing account it will be clean-, I think, how this mis¬ 
conception has arisen. 
