456 VETERINARY BACTERIOLOGY 



A. Sporozoa found in the blood -cells. 



1. In the erythrocytes. 



a. At some stage occupying a considerable proportion of the interior of 



the cell. 



(1) In mammalian blood. 



Well-differentiated, usually pear-shaped bodies, often two in a cell. 



In animals Piroplasma or Babesia. 



Ameboid at first, finally filling the cell. In man Plasmodium. 



(2) In blood of birds Proteosoma, Halteridium, Hemoproteus, 



b. Forming minute dots, seemingly entirely of chromatin. . .Anaplasma. 



2. In the leukocytes Leukocytozoon. 



B. Sporozoa in muscles Sarcocystitis and Balbiana. 



C. Sporozoa usually hi membranes (mucous or serous) Coccidium. 



THE GENUS PIROPLASMA, OR BABESIA 



An organism belonging to this genus was first noted by Babes 

 and called by him Haematococcus. Theobald Smith, in 1889, made 

 the first observation which related one of these organisms to 

 Texas fever. He called the organism Pyrosoma. This was later 

 changed to Piroplasma by Patton, and still later by Starcovici to 

 Babesia. 



The organisms of this genus occur in the red blood-cells of 

 various mammals and produce several distinct diseases. The life- 

 history of all the species has not been satisfactorily worked out. 



Piroplasma bigeminum 



Synonyms. Pyrosoma bigeminum; Apiosoma bigeminum; Babe- 

 sia bigeminum bovis; Hcematococcus bovis; Ixidoplasma bigeminum. 



Disease Produced. Texas fever, or tick fever in cattle bovine 

 piroplasmosis. 



Theobald Smith, in 1889, discovered the cause of Texas fever 

 in cattle. His work was fundamental and remarkably complete 1 . 

 Since that time investigators have found the same organims in 

 many countries. 



Distribution. Southern United States, Australia, Argentina, 

 Europe, India, and Africa. 



Morphology. In the blood of infected animals the organisms 

 are generally in pairs. They are commonlv piriform, one end In MI IK 

 rounded and the other somewhat pointed. The acute ends are 

 usually pointed toward each other. The organisms vary from 

 0.5 to 4 (A in diameter. The reproductive stages have not been 



