458 VETERINARY BACTERIOLOGY 



countries. The female tick becomes engorged with blood and falls 

 to the ground, where, after a time, eggs are laid. They hatch in 

 from nineteen days to five or six months, depending upon the 

 temperature conditions. The young ticks crawl up the stems of 

 grass and shrubs. They must get upon the body of an animal or 

 die of starvation. The ticks from an infected mother are them- 

 selves infective, and may transmit the disease to the animal whose 

 blood they suck. 



Piroplasma parvum 



Synonyms. Babesia parva; Theileria parva. 



Disease Produced. East African coast fever, Rhodesian red- 

 water, Rhodesian tick fever in cattle. 



The organism and the disease have been studied by Theiler, 

 Koch, and others. This protozoan is the smallest of the Piro- 

 plasmas known. In the red cells it forms a small rod that has 

 a chromatin granule at one end. Frequently ring forms are ob- 

 served, never the pear-shaped types of P. bigeminum. Gonder 

 has worked out in detail the life-history of the organism. This 

 disease is peculiar, in that transference of blood containing the or- 

 ganism from one animal to another does not resu't in the transfer- 

 ence of the disease. Repeated inoculations are without effect. 

 It is transmitted by means of the brown t'ck (Rhipicephalus ap- 

 pendiculatus) and the black pitted tick (Rh. simus). The affected 

 animal shows high fever and swelling of the lymph-nodes. Anemia, 

 icterus, and hemoglobinuria are rare'y observed. Immunity to 

 this disease does not immunize against Texas fever. What is 

 probably the same disease has also been described from southern 

 Russia and in Java. 



Piroplasma mutatis 



Theiler has established the presence of a third piroplasmosis 

 in southern Africa, due to a protozoan which he has named P. 

 mutans. It is smaller than the P. bigeminum, and animals im- 

 munized against one will contract the other. 



Pfroplasma' cqui 



Disease Produced. Equine biliary fever. Equine piroplas- 

 mosis. 



Guglienni, in 1899, discovered this organism in Italy, and 



