238 
Drug Treatment of Redwater 
No. of passages 
through animals 
Coio 5 (which received treatment) was inoculated 3. vi. 1909 with 200 c.c. of defibri- 
nated blood from Heifer 108, but having failed to react by the 13th day 
the cow was reinoculated on 15. vi. 1909 with 30 c.c. of jugular blood 
taken 2 hours after death from our Control Cow I. 
6. All of our remaining cows (Controls I—IV, Treated Cows 1—4), 8 in all, were each of 
them inoculated with 30 c.c. of defibrinated blood from Cow X on 
7. vi. 1909. As will be seen by reference to their protocols (pp. 244, 
252 et seq.) all of these animals developed piroplasmosis. 
As will be seen by reference to the foregoing record the history of 
the strain starts with (1) The initial case which was induced by means 
of infected ticks. This and the succeeding case, the first due to 
inoculation, ran a very mild course. The cases induced by subsequent 
inoculations (Passages 3 and 4, etc.) were severer. 
The Cattle used for our Experiments. 
The animals used in our experiments were purchased in the open 
market. In view of the limited means at our disposal, the cattle were 
of inferior quality. The majority were shorthorns,—two were Jerseys. 
Cows IV (Control) and 4 (Treated) were in poor condition at the start. 
Excluding Cow X, with whose blood eight of the experimental animals 
were inoculated, we had nine animals at our disposal for the purpose of 
experiment. Of these animals four served as Controls and five were 
subjected to treatment. 
Methods of Investigation. 
The cows were in all cases inoculated subcutaneously with blood 
obtained from the jugular vein of animals infected with P. hovis. In 
most instances the blood had been defibrinated prior to injection. The 
Trypanblau was prepared in saturated watery solution (cold) and injected 
in quantities of 130 to 200 c.c. Four of the treated cows received the 
drug intravenously, whilst the fifth cow was treated subcutaneously. 
The rest of our technique was precisely the same as that adopted in 
our experiments on dogs. Consequently we refer the reader to our 
previous paper (particularly to p. 161) where we describe our method of 
enumerating the different forms of intracorpuscular parasites as recorded 
in the protocols. 
In the blood counts which accompany all our protocols the per¬ 
centage of infected corpuscles was usually determined by counting 500 
