G. H. F. Nuttall 
109 
stage. My laboratory assistant, Mr B. G. Clarke, aided me considerably 
in the search for parasites. In all, we discovered 98 parasites, of which 
eight were haemogregarines. 
Piroplasma rossi n.sp. 
Plate X. 
It is with hesitation that I place this parasite in the genus Piro¬ 
plasma, and I only do so provisionally for reasons about to be described. 
On the other hand, it appears safe to refer the protozoon to the Family 
Piroplasrnidae of Franga. Were it not for the fact that I have recently 
discovered somewhat similar parasites in the internal organs of a dog 
235 days after it had been inoculated with Piroplasma canis, the dog 
having recovered in consequence of trypanblue treatment (see Para¬ 
sitology, Vol. ii. p. 180), I should unhesitatingly have referred the para¬ 
site of the jackal to a new genus. Only two parasites were encountered 
in the dog, and it will be necessary to examine other animals before any 
conclusions can be reached regarding the resemblance existing between 
the parasites. The parasites of the jackal differ very markedly from 
P. canis as observed in the peripheral blood during the normal course of 
piroplasmosis. Thus, in the jackal parasite there is an absence of the 
typical pairs of pyriforms and the characteristic dividing (“budding”) 
forms are lacking; the nucleus is, moreover, very much larger and 
differs from that of P. canis, as elsewhere described by Dr Graham- 
Smith and myself. When we come to examine smears from the organs 
of dogs, long after the animals have “recovered,” with the same care 
that we have devoted to the examination of the smears from the jackal, 
we shall be in a better position to express an opinion on the subject. It 
is conceivable that the parasites of the jackal represent a special form 
of Piroplasma occurring in animals which suffer from a chronic infec¬ 
tion or which have recovered from acute piroplasmosis. To my knowledge 
parasites have not hitherto been described from animals after “recovery” 
from piroplasmosis. We know that they are present in peripheral blood 
because the blood of “salted” animals is infective for months or years 
although failure has attended the efforts made to detect the parasites 
by microscopic examinations. Assuming, on the other hand, that the 
parasite of the jackal is a Piroplasma of an hitherto undescribed type 
and peculiar to recovered animals, it may well be referred to a new 
species in view of the host in which it is found, for, as we have recorded 
