G. H. F. NuTTALii AND C. Strickland 
7U 
(B) The stained parasites. 
A study of the stained parasites (Diagram VIII) shows that they 
are very closely allied to P. bovis, the large parasites being less 
actively amoeboid than in P. canis, and tending to assume a piriform 
shape. The chromatin structures are identical with those of P. bovis. 
The reader is referred to the Appendix for particulars relating to the 
course of the disease in the horses upon which we experimented 
(P. caballi Horses I, II and III). 
Time when the parasites appeared in the blood. Percentage 
of infected corpuscles, etc. 
Horse I. The parasites appeared in the blood on the 15th day 
after inoculation ; they had increased slightly in numbers by the 
18th day. The horse died on the 19th day from pulmonary hae¬ 
morrhage. The disease (piroplasmosis), being but in the initial stage, 
the organs showed no distinct lesions. 
Horse II. A few parasites appeai'ed on the eighth day after inocu¬ 
lation and then disappeared, the animal recovering. 
Horse III. The parasites appeared on the tenth day after 
inoculation ; by the 13th day only 6 per 30,000 corpuscles were found 
infected, after which there was an intermittent increase of parasites ; 
but even on the 19th day, when the horse died, only 0'5 “/o of the 
corpuscles were found to contain parasites. 
At autopsy, this horse showed marked jaundice of the mucous 
membranes and subcutaneous tissues; the lungs were congested, the 
kidneys oedematous; the spleen was much enlarged, semi-fluid and 
very friable; it weighed 15^ lbs.; the liver was enlarged. 
A rise in body-temperature preceded the appearance of the parasites 
in the blood of the thi’ee horses. 
The types of parasites observed. 
Consideration of the types of parasites encountered in the peripheral 
blood during life shows that the predominant forms are round (0) or 
double piriforms (PP). In Horses I and II only (0) and (PP) wei-e 
found in the blood, but they were very scarce. Other typical 
forms were however encountered in the blood of Horse III whilst 
it lived, and in this case counts of the different types were rendered 
