281 
round chromatin mass, and the protoplasm projects as a 
circlet of rays (i). Forms occur in which two club- 
shaped parasites have stuck together in their long axis 
or £ copulated ’ (2). All these rays are eventually 
withdrawn, and from the second to third day spherical 
forms of increased volume occur (3). 
On the third day structures appear whose relation¬ 
ship to the previous forms is at present unknown. They 
Fig. 91 Development of P. bigeminum according to Koch 
consist of immense numbers of amoeba-like piroplasma 
forms, surrounding a large nucleus possibly that of 
a body cell (4). The chromatin in these parasites 
consists of scattered granules. The parasites separate 
from the heaps and grow, and the chromatin con¬ 
denses. They now have a characteristic club shape (5). 
These forms are seen also in the eggs of ticks. The 
developmental cycle has not been further traced by 
Koch, but cp. P. canis. 
2. P. parvum .—Is found in cattle on the East 
coast of Africa, etc., and a similar, if not identical, 
