CANINE PIROPLASMOSIS 125 



The changes which the parasite undergoes in ameboid movement 

 are best seen during the febrile period. The most varied ameboid 

 forms are found toward the end of the febrile period (Nocard and 

 Motas). The infected corpuscles are larger and paler than other 

 corpuscles. The parasites appear as small rounded bodies having 

 a dark contour and refractive central part. Very soon after the 

 febrile period the parasites lose their ameboid properties, take on 

 a rounded form and remain immobile in the center of the affected 

 corpuscles. At the beginning of the disease only a single parasite 

 is found in each infected corpuscle; later infected corpuscles often 

 contain several parasites, when pyriform parasites may be found, 

 though they are rare (Nocard and Motas). Though the parasites 

 may be found in fresh blood when they are numerous, they are 

 much more readily found in stained preparations. Some one of 

 the modifications of the Romanowsky method is preferable. 

 Nuttall and Graham-Smith obtained excellent results using Leish- 

 man's modification. With this stain the parasite appears as a 

 blue body containing usually a single homogenous chromatin body 

 (karyosome) which stains a bright red. In larger forms the cell 

 body has frequently a vacuolated or trabecular structure and 

 appears condensed at the periphery. Small spherical forms often 

 appear as rings, resembling young malarial parasites in man. In 

 dividing forms a delicate protoplasmic thread may for some time 

 join the daughter cells. With pyriform parasites the connecting 

 thread is usually at the pointed ends, with other forms the con- 

 necting threads are somewhat irregularly situated. The chro- 

 matin body is usually spherical and is usually centrally situated, 

 though it is sometimes eccentric or peripheral. In dividing forms 

 the chromatin body becomes elongated and separates into two 

 portions, immediately followed by division of the cell body. Both 

 spherical and pyriform parasites undergo division (direct division). 

 In the acute form of the disease several parasites, two to 16, 

 may be found in a corpuscle; in the chronic form it is rare to find 

 several parasites in the same corpuscle. Corpuscles may be found 

 containing one to 16 or even more parasites. In the very beginning 

 of the disease only a single parasite is found in a corpuscle, later 

 the infected corpuscles often contain several. Those containing 

 several parasites, eight to 16 or more, are found more often in 

 blood from the internal organs, brain, lymphatic glands, bone 



