284 
Development in the Tick. — P. parvum passes through 
similar changes to P. bigeminum as far as the forms 
depicted in Fig. 91, but the amoeba-like forms 
(Fig. 91 (4)) have not been seen. 
3. P. annulatum (Dschunkowsky and Luhs).—In 
cattle in Transkaukasia and Egypt. 
Symptoms. —(1) Acute form: daily rises of tempera¬ 
ture to 41 0 for one to two weeks. Temperature then 
remains high. Pulse one hundred and twenty, thread¬ 
like. Respirations thirty-six. Haemoglobinuria seldom. 
Convulsions. Death. (2) Chronic form : characterised 
by icterus and progressive weakness and great anaemia. 
Blood Examination. —Acute form : over ninety 
per cent, of the red cells are infected. Bacillary and 
ring forms occur. Chronic form : ten to forty per cent, 
of cells are infected, and only cocciform or punctiform 
parasites are found. 
Pathology. —Extensive haemorrhages in most 
organs. In the abomasum (fourth stomach) occur 
characteristic haemorrhagic ulcers. Cp. P. parvum. 
Transmission .—(1) Susceptible cattle can be 
infected by inoculation. (2) The carrier is M. calca- 
ratus , a variety, according to Donitz, of M. annulatus. 
4. P. mutans (Theiler).—In cattle in the Trans¬ 
vaal, in the blood together with P. bigeminum. Differs 
from this by the fact that it produces minute bacillary 
and ‘ cross ’ forms as is the case with P. parvum , but 
is not the same as this though morphologically very 
similar ; as it is inoculable. P. annulatum is separated 
by its morphology and pathological effects. In order 
to distinguish from P. parvum , several blood examina¬ 
tions must be made ; this form increasing rapidly in 
numbers, while P. mutans is always scanty. 
Transmission. —By inoculation of blood. 
Similar associations of P. bigeminum and bacillary 
