32 
NOTES ON THE COMMON PATHOGENIC 
Genus, Babesia. Starcoviei, 1893. 
~ ( Pyrosoma. Smith and Kilborn, 1893. 
Synonyms | Pmplasma _ Paton> 1895 . 
Babesia bigemina. Smith and Kilborn, 1893. 
Syn -1 ^ ro V^ asma bigeminum. 
‘ * \ Piroplasma bovis. 
Hosts. Cattle. 
Distribution. First described by Smith and Kilborn, 1893, 
as the cause of Texas Fever in North America, this parasite 
has a wide distribution throughout the world and is associated 
with the disease known as Kedwater in cattle. It is probably 
universally distributed in East Africa. 
Morphology. The typical form is a twin pear-shaped body 
lying within a red blood corpuscle. Each pear measures 
from 2ya to 4 ya in length and about 1/u in breadth at the blunt 
extremity. Round and irregular forms, measuring from 1*5 p 
to 2-5ya in diameter, are also found. Parasites free in the 
plasma are also encountered. According to the researches of 
Nuttall and his co-workers on this parasite and on Babesia 
canis, the intra-corpuscular development is simple ; the pear- 
shaped forms becoming round, then ovoid, and finally dividing 
into two by a process of budding. This Nuttall regards as an 
essential characteristic of the genus Babesia. Certain authors 
(Doflein, Lignieres, Bowhill) have described flagellated forms 
as occurring, and regard these as analogous to the microgamete 
flagellation in other Protozoa. 
Transmission is effected by means of a tick. Species of 
the genus Boophilus curtis are mainly responsible, B. annulatus 
in America and B. decoloratus (the blue tick) in Africa. This 
genus of tick requires but one host, that is to say a larva 
having once reached an animal remains thereon throughout 
its full cycle, the changes into nympha and adult being effected 
without dropping off to the ground. Larvae born of mothers 
which fed on an infected animal are capable of transmitting 
the parasite, which therefore passes through the egg. The 
credit of this discovery is due to Smith and Kilborn. 
Pathogenesis. This parasite is the cause of Redwater in 
