G. H. F. Nuttall 
305 
endemic. The blood of “ salted ” dogs and cattle has been found to be 
infective for three to eight years after the acute attack has subsided. 
In nature, piroplasmosis is transmitted only by ticks which have 
previously fed upon infected animals either in the acute stage of the 
disease or in the “salted” condition. It is owing to indigenous animals 
being “ salted ” in regions where piroplasmosis is endemic that the ticks 
of the region continue to harbour the parasite and constitute a potential 
source of danger to freshly imported animals coming from places where 
the disease is absent. 
Bovine Pirojdasmosis. 
» Bovine piroplasmosis is due to at least two species of Piroplasma: 
P. hovis and P. divergens. 
The latter pai’asite (Fig. 2) judging from specimens which have 
reached me hitherto is confined to Europe, and in nature is transmitted 
Fig. 2. Piroplasma divergens: progressive stages of development corresponding to those 
observed in P. hovis (q.v.) ; the parasite is, however, much smaller than P. hovis, 
although occasionally fairly large piriforms (16) may be encountered. (Original, 
G. H. F. N. del.) 
by Ixodes riciniis^, the common European cattle tick. I have received 
specimens of P. divei’gens and I. ricvmis from cattle suffering from 
“redwater” in Norway, Germany, Kussia, Hungary, Great Britain, and 
Ireland, and I know that this form of redwater occurs in Finland, Sweden 
1 See Description in Ticks, Part II, pp. 143, 293, 334 and Parasitology, vi. p. 91. 
