8 
Cycle 
showing the usual mode 
of multiplication 
of 
Piroplasma canis 
in the circulating blood. 
13 
Fig. 1. Piroplasma caiiis: (1) a free piriform parasite which has just left a blood 
corpuscle enter.s a normal corpuscle and (2-4) assumes a rounded form, remaining 
quiescent for a time after which it grows in size. It then becomes actively amoeboid 
(5, 6), and again becomes rounded (7). Two symmetrical processes (8-10) are then 
protruded, which rapidly enlarge at the expense of the body of the parasite. Each of 
these processes (11-13) gives rise to a mature piriform parasite, which remains 
attached to its fellow by a thin strand of protoplasm. The parasites next become 
separated (14) and, by active swimming movements, burst out of the corpuscle (15) 
whose haemoglobin escapes into the plasma. The free parasite immediately re-enters 
a fresh corpuscle. (Nuttall and Graham-Smith, 1907.) 
