Gr. H. F. Nutt all and S. Hadwen 
237 
effects upon the bovine parasite to those observed in the case of 
Piroplasma canis. The object of this paper is to describe in detail our 
experiments upon the curative treatment of bovine piroplasmosis 
(Redwater or Texas Fever) by means of trypanblau. 
Our experiments on Redwater were rendered possible through the 
help of the Colonial Office and of the Board of Agriculture and 
Fisheries. We are much indebted to H. J. Read, Esq., C.M.G., of the 
Colonial Office, for the kind interest he has taken in our work, and we 
take this occasion to thank Messrs Stewart Stockman, M.R.C.V.S. 
(Chief Veterinary Officer of the Board), James R. Jackson, M.R.C.V.S., 
and W. G. Wragg, M.R.C.V.S., for the very friendly help they gave us 
during the prosecution of our experiments in the Laboratory of the 
Board of Agriculture and Fisheries at Alperton, Wembley, Middlesex. 
History of the strain of Piroplasma bovis used in these experiments. 
We are indebted to Mr J. R. Jackson for the following particulars 
regarding the strain of South African Piroplasma bovis used for the 
inoculation of the cattle upon which we experimented: 
No. of passages 
through animals 
1. Initial Case. On 9. vii. 1904 a calf, 3 months old, was infested with Boophilus deco- 
loratus larvae obtained from South Africa. The calf did not develop 
symptoms, and no P. bovis were found in its blood. (Sir John Mac- 
Fadyean’s case.) 
2. Yearling Bull 9 was inoculated 13. iv. 1905 with 5 c.c. of defibrinated blood taken from 
the initial case. The bull developed no symptoms, but a few P. bovis 
were detected in its blood on 22. iv. 1905. 
3. Heifer 5 was inoculated on 2. xii. 1905 with 5 c.c. of undefibrinated blood taken from 
the jugular vein of Bull 9. The heifer developed fever and P. bovis 
were detected in its blood on 11. xii. 1905. The heifer suffered from 
severe piroplasmosis but made a slow and steady recovery. 
4. Heifer 108 was inoculated 5. ix. 1907 with 50 c.c. of defibrinated blood from Heifer 5. 
The animal developed fever and P. bovis were detected in its blood on 
13. rx. 1907; the case was a severe one but recovery was rapid. 
With a view to assuring ourselves of the virulence of the strain 
maintained in Heifer 108 since September, 1907, two cows were 
inoculated by Mr Stockman with its blood as follows: 
5. Cow X was inoculated 22. v. 1909 with 30 c.c. of defibrinated blood from Heifer 108, 
but having failed to react (see Protocol, p. 241) the cow was reinoculated 
after 13 days with 200 c.c. of defibrinated blood from Heifer 108. The 
cow showed parasites on the 16th day after the first inoculation. 
