Protozoan Ictero-hcematuria in Sheep, etc. 575 



erations of these, a spring and an autumn one, in the same 

 season, or otherwise a restriction of such invertebrate to the low 

 valley pastures and the alkaline bogs on the higher levels, and 

 that they disappear from the drier, arid areas in summer. It 

 cannot be an obligate parasite like a louse or melophagus which 

 would be constantly present, nor a musquito absent in early 

 spring. But up to the present no invertebrate host or intermedi- 

 ate bearer has been identified. Cases were at first reported in 

 the Angora goat, but this animal is now known to be immune. 



Microbiology. The parasite is formed in the red globules and 

 blood serum of the affected sheep and closely resembles the mi- 

 crobe of Texas fever. In the blood globules the parasite is seen 

 in different forms, round, oval, oblong or curved and from one 

 tenth to one sixth the diameter of the red globule. A single red 

 globule may show from one to four of the microorganisms. They 

 may at times show indications of division, and at others, auto- 

 matic amoeboid movements, from one portion of the blood globule 

 to another, or from the periphery toward the centre. The affected 

 blood globules are usually enlarged, having lost their biconcave 

 outline, and become biconvex or spherical, with irregular crenated 

 surface, and a dull, lustreless appearance instead of a clear red or 

 yellow aspect. The protozoon stains readily in anilin red or 

 methylene blue. 



Lesions. The condition of the carcass was good or even high, 

 in sheep attacked when in good flesh, and in which the affection 

 ran a rapid and fatal course. In sheep attacked while in low 

 condition on the other hand, the case tended to be milder and 

 more prolonged, and the body was emaciated and anaemic. 

 Dropsical swellings were common on the ears and sides of the 

 head and neck. 



The skin, connective tissue, fat, and other normally white 

 tissues were usually of a yellow color, varying from sulphur to 

 lemon color. The muscles were pale and soft with a yellowish 

 tinge. 



The blood was pale, thin and watery, especially in protracted 

 cases, formed a loose coagulum, or remained fluid with a grayish 

 red color. There was marked leucocytosis (1:4 or 5). 



The stomach and intestines were more or less icteric, and con- 

 tained little ingesta. 



