ItKL'OllT ON DOUIUNE. 



inoculable into one or other species. The Pyroplastnata have 

 Invu classified up to the present as follows : 



(i) Piroplasma bigemiuum . P. of ox. 



(ii) equi . horee. 



(iii) . ovis . sheep, 



(iv) canis . ,, dog. 



The organisms penetrate into the red corpuscle? of their host 

 and bring about their destruction in acute cases, the principal 

 symptoms presented being anaemia, bsemoglobinuria, and jaundice 

 more or less marked. It is known that the disease is carried to 

 bo vines and canines by various species of ticks (ixodes), and there 

 is but little doubt that in the other animals attacked ticks may also 

 act as carriers. The disease caused by the presence of the above- 

 mentioned Pyroplasmata may he either an acute or a mild form. 

 In most countries the acute form makes its appearance in the 

 summer and autumn, while the mild form usually is present during 

 the winter or early spring 1 , but the two forms of the malady may 

 be present and run their course in different animals of the same 

 species, belonging to the same herd concurrently, during the same 

 season of the year. The various forms of Pyroplasmata which 

 bring about disease in the different species of animals above men- 

 tioned belong to the class protozoa. They vary considerably 

 in form, presenting pear-shaped, oval, spherical, and round bodies, 

 for the most part occupying the interior of the red corpuscles, but 

 are also not frequently found in varying numbers in the blood 

 plasma. As to size, they vary very much from time to time in the 

 same host, but the range is from a mere speck 0'25 to 3'5 mikrons 

 in length. In bovines the Pyroplasmata are associated in pairs, 

 but in other animals, and occasionally also in the former, one finds 

 them in multiples of two up to eight in one corpuscle, but the 

 latter number is the maximum and rare. Each pair of organisms 

 are connected in some way to each other, generally iu P. biyeminnm, 

 by a very fine filament extending from their tapering extremities, 

 In the red corpuscles they are endowed with amoeboid movements 

 and are but rarely observed to occupy the same position for long in 

 fresh specimens of blood. 



(a) Texas Fever. In December 1902, I reported to Govern* 

 meut that Heemoglobimiria or Texas Fever due to the presence of 



