1132 PATHOGENIC PROTOZOA 



freed hemoglobin is excreted by the kidneys, producing the disease 

 variously known as red water fever, Texas or Southern cattle fever, 

 tick fever, bovine malaria, hemoglobinuria, and others. The parasite 

 is small, two to four microns long and one to two wide, and character- 

 istically occurs in pairs, the narrow ends being united. When the 

 parasite is mature the two daughter cells separate and when liberated 

 by the degenerated erythrocyte attack new red cells. The pear-shaped 

 babesia enters a new cell by its broad end, becomes rounded or ring- 

 like, then ameboid in form, and finally the nucleus sends out a bud; 

 this divides into two by forking, and as the nuclear matter continues 



FIG. 162. BABESIA BIGEMINUM. (Army Med. School Collection, 

 Washington, D. C.) 



to grow each portion becomes surrounded by cytoplasm and ultimately 

 the two new daughter cells separate from one another. Multiple 

 infections of single red cells are common, as many as sixteen pairs 

 having been seen in a single cell. 



Good preparations for clinical work are obtained by some one of 

 the Romanowski stains, but the finer details of the nucleus and cell 

 division can only be studied after iron hemotoxylin staining. 



The parasites, with the exception of T'heileria parva, do not disap- 

 pear completely from the blood after the animal recovers from its 

 illness, but remain indefinitely in the circulation, and their continued 

 presence and virulence may be demonstrated by the inoculation and 

 non-immune animals with blood from an animal which has recovered. 



