236 CLINICAL DIAGNOSTICS. 



preaching each other, or in actual contact. They are 2.5-4 micra 

 long and 1.5 to 2 micra wide. Two per cent, of the red corpuscles 

 in the circulating blood are infected, while 50% of the red corpus- 

 cles of the capillaries of the organs contain the parasites. 



The presence of the parasites is easily demonstrated by fixing 

 smear preparations in absolute alcohol and staining with alkaline 

 methylene blue. 



Texas Fever. Is an infectious disease of cattle caused by 

 Pyrosoma bigeminum [indirectly by the presence of Texas fever 

 ticks, Boophilus bovis]. Period of incubation 10-15 days. High 

 and continuous fever, rapidly progressing anemia, red corpuscles 

 reduced in number from six million to one million per cc. Hema- 

 globinuria. Fatal termination the rule. 



Pyrosoma bigeminum is a minute pale protozoon of 

 a roundish form found in the red corpuscles. It possesses ame- 

 boid movement and can therefore assume irregular shapes. When 

 fully developed the parasites occur as two pear-shaped bodies with 



Fig. 56. 



Different stages of development of Pyrosoma bigeminum in red blood corpuscles. 



their pointed ends, converging. They are 2.5 to 4 micra long and 

 1.5 to 2 micra wide. In the circulating blood 1 to 2% of the blood 

 corpuscles are infected, in the capillaries of the various organs 

 more than half of them contain the parasites. 



Malaria A non-contagious infectious disease caused bj' Plas- 

 modium malariae. Remittent fever, pronounced icterus, petechiae, 

 cerebral depression, small rapid pulse. Loss of appetite, increased 

 thirst, dark-colored urine staining white hair A'ellow. The malaria 

 parasites which occur in tlie blood constitute a special group of 

 protozoons. They differ from the Pyrosoma in being pigmented. 

 They may be stained with methylene blue. They are bright 

 roundish bodies with distinct outline, occurring singly in the red 

 blood corpuscles. 



Flagellosis of horses. ^lal de Caderas. Gradually rising re- 

 current fever rarely exceeding 40° C. (104° F.) Rapid' emaciation 

 in spite of good appetite. Paralysis of the hind quarters, bladder 

 and rectum. Edema, hemoglobinuria, continuous lying down, 

 coma, death. The specific cause of the disease, Trypanosoma 

 equina (Flagellata) is found in the blood as an actively motile 

 parasite. Smear preparations may be stained in 15-20 minutes 

 with carbol-fuchsin to which has been added one-third volume of 

 glycerine. Magenta red, however, is a better stain. The parasite 

 has the form of a whip lash and is three or four times the length 



[Malkmus regards this disease and hemoglobinuria of cattle (Europe) as very proba- 

 bly identical.]— Translators. 



