PROTOZOA 389 



time when they are numerous and motile. The parasites are 

 irregular and have a dark contour in the somewhat large and 

 pale blood corpuscle. Corpuscles are not appreciably en- 

 larged when they contain from but one to six parasites but 

 when the number is greater than this they are somewhat en- 

 larged. 



Staining 1 . A number of staining solutions have been 

 recommended. Marchoux used Laveran's stain which colors 

 the chromatin violet red. Nocard and Motas use Nicole's 

 carbol-thionin to stain films dried in the air, fixed in absolute 

 alcohol and stained for 30 seconds. With this the corpuscles 

 appear a pale green, the parasites a dark blue and sharply 

 defined, their central portion remaining unstained or staining 

 a pale blue. 



Graham Smith 3 described in detail the morbid anatomy 

 of piroplasmosis in dogs. In this he gives the percentage of 

 corpuscles infected in smears made from the different organs. 

 These vary from less than 1 to 50 per cent or more. His ex- 

 amination shows that over 9.1 per cent of all infected corpuscles 

 contain either 1 or 2 parasites only and that 98 per cent con- 

 tain from 1 to 4. Even numbers of parasites were present in, 

 97.11 per cent of all infected corpuscles containing more than 

 one parasite and odd numbers were present in only 2.88 per 

 cent of the infected corpuscles. 



PIROPLASMA PARVUM THEILER. 



Synonyms. Theileria parva; B&besia parva. 



Place in nature. P. parvum is the cause of the East Coast 

 fever of Southern Africa. This name was given to the so- 

 called Rhodesian redwater by Koch in 1903. Certain authori- 

 ties in Asia Minor have assigned to it the more scientifically 

 correct name of tropical piroplasmosis. This is a specific dis- 

 ease affecting cattle, characterized by a high temperature, the 

 presence of a specific piroplasma (P. parvum) in the red blood 

 corpuscles, a heavy mortality and by not being directly trans- 



:! Graham Smith. Jour, of Hyg., Vol. V (1905) p. 250. 



